- In the beginning cut-scene, Soap says "We've got one good UMP, they've got a thousand" to illustrate how out-gunned they are compared to Shepherd's men. Interestingly, even though he says this, neither Price nor Soap have a UMP, but a SCAR-H and Vector instead, respectively. However, in the French version of the game, Soap talks about submachine guns, and does not mention the UMP at all.
- When the player takes out the first group in the beginning of the level, Price sometimes says, "Dog neutralized. I count five tangos down." However, this happens only if Price kills the dog. If the player instead kills the dog before Price does, Price will say "Just like old times," referring to when he and Soap worked together during the events of Call of Duty 4: Modern Warfare.
- Early on in the level, when Price talks his lips do not move. This occurs in various times through the campaign.
- If the player alerts the guards at the beginning, they can run up the slope while the player can only slide down.
- When taking out the first group of guards, Price fires his Intervention faster than is physically possible, as he doesn't cycle the bolt.
- If the player throws a grenade at the Shadow Company patrol at the beginning of the level the explosion will turn out pixelated.
- The Vector the player starts with as their secondary weapon has a unique black finish.
- At the beginning of the level when Nikolai flies away from Soap and Price after Price says "Don't bother. This is a one way flight, mate." Nikolai says "Then good luck, my friend." he can be heard saying "Thank God" in Russian.
- Just before the rappelling sequence, if the player looks to the left, they can see through the cave walls and onto the edge of the mountain where the player will later walk on the metal catwalks with the riot shield.
- If the player looks at Price's Intervention just before they snipe the patrols, they can see there doesn't seem to be a magazine in the weapon.
- Sometimes, after picking up an enemy weapon, Price will say "Make sure you're using a supressed weapon, otherwise you're dead." Occasionaly a glitch may occur and Price will say this as you enter the cave network.
- If Soap is attacked by the dog in the beginning and manages to break its neck, the character model for a US Ranger is used.
- One of the soldiers may carry Akimbo TMPs.
- When looking at the tunnel, one will notice civilian cars.
- Before either rappelling down the cliff or after rappelling and killing the guards, the player can see civilian cars on the other side of the canyon. If he/she scopes in with his/her Intervention to look closer, the player can see no one is driving them. They are the same model but their color is randomly generated. Although, the player obviously can't see the cave system itself, the large flights of Little Birds do little to preserve the secrecy of the site. Later on during the mission, after Shadow Company acknowledges Soap's and Price's presence, they're forced to traverse the rock bridge. When moving across the bridge the player can see tanks and Humvees moving across instead of civilian vehicles.
- Price says "This decryption code better be worth the price we paid", which is a near exact quote from Return of the Jedi.
- Directly below the hill that Price and Soap slide down after killing the enemy patrol, there is a spot where the player can jump off the cliff and survive. When the player lands, a mission failure screen appears saying "Friendly fire will not be tolerated!"
- When Soap and Price are rappelling down the cliff, Price's shadow is visible on the ground near the guards. One will look at Price's shadow, but will not react to it. The guard below Soap however will look up and see Soap if the player takes too long to kill him.
- On lower difficulty levels the game will brake automatically upon reaching the bottom after rappelling down. On higher difficulties the player will fly off the cliff if they do not brake.
- For some reason, the two guards that Soap and Price knife after rappelling carry silenced weapons. The soldier that Soap knifed has a MP5K Silenced Red Dot, while the one you knifed has a Vector ACOG Silenced. It is possible the two guards may be unreliable as loud noises from shooting the guns would alert the soldiers in the cave.
- Regardless of when you start, what difficulty, or even restarting the mission (which results in the enemies carrying different weapons), the two soldiers guarding the cave entrance will always have the two weapons mentioned above.
- When rappelling down, the player will automatically switch to the Vector ACOG silenced, even if their weapon before rappelling down was a different weapon.
- After knifing the soldiers, when you move your arm away from the dead soldier the Vector ACOG silenced will spawn in a pre-set position.
- The two guards model appearance are always the same.
- When going across the bridge if the players uses noclip and go down to river he/she can see Shadow Company soldiers in Zodiacs, oddly their weapons are under the Zodiacs.
- When rappelling down, the Zodiacs do not appear until you reach a position where it blocks your view of the river. After moving from that position two Zodiacs will appear.
- There is one little notable thing in this mission: when Price executes a Shadow Company soldier with a knife from back is the same animation when he kills a Russian guard with a knife too at the same way in the Call of Duty 4: Modern Warfare in the mission "Ultimatum" in the house before to rescue Griggs.
- Sometimes, if the player falls off the cliff before hooking up, a message will appear with the players death, saying "KILL_DEATHQUOTE_QUOTE".
In the first caveEdit
- The soldier that is watching the TV (the one who can be spared) is watching security footage of "The Gulag".
- Before Price goes to kill the guard at the top of the staircase, he says "He's mine." If the player kills the guard before Price does, he will say "Never mind, then.", similar to Soap in "Cliffhanger". Sometimes he won't respond if the player kills the guard quickly enough.
- When the player is in the tunnel system and the two soldiers come through the door with the stairs and the red light, if they can kill them both, Price will say "Impressive."
- After avoiding the first patrol in the cave and then taking out the guard the patrol passes, the player can stealthily follow the patrol to where they are headed. The patrol walks to the entrance of the cave and then stops. One soldier in the rear of the patrol will turn and spot the player, alerting the rest of the group. If the player listens to their comms, the patrol does indeed find the bodies of the guards at the cave entrance (indicated by one of them saying, "We got a man down!"). This is likely how Shadow Company knows Soap and Price are there and ambushes them in the 'steam room' later on.
- The guard which Price tells the player not to engage when they first enter the cave seems to be smoking and blowing smoke through his balaclava.
- When you kill the smoking guard, Price will tell you to move quickly. Afterwards, Price will say "The guards know something's not right. Stay out of sight." If you don't move to the area with the canvas, even if you hide behind a wall, Price will unintentionally alert the soldiers.
- If you leave the cave, Price will say "Soap, where are you going?" afterwards, you will recieve a mission failure saying "You abandoned Price."
- In the cave among the other Shadow Company soldiers there are two men playing chess. Also, if the player keeps watching, one of the chess players will whack the other man's head to get his attention.
- If you sneak past all of the soldiers, eventually Shadow Company will say "Disciple Five, we've lost all contact with Disciple Four. Check it out, over." The same will happen even if you kill all of the soldiers in the cave. "Disciple Five" was the large patrol that was leaving the cave to check on "Disciple Four" (the patrol at the beginning).
- If the player follows the large patrol when first entering the cave, they will still use their flashlights when they exit the cave.
Steam room and CatwalkEdit
- The instructions from Shadow Company HQ to "Terminate with extreme prejudice" is a reference to Captain Willard's mission in the 1979 movie Apocalypse Now.
- The ACRs that have Silencers, Red Dot Sights, and Heartbeat Sensors found on a rack in the steam room that Shadow Company breaches have a unique black paint job and a max ammo of 1260. If the player picks up any of the three, then switched to his or her secondary weapon and swapped it for another fully-loaded ACR, he or she will end up with a total ammo loadout of 1890 rounds, or the equivalent of 63 magazines' worth of firepower, excluding the ammo already in both weapon's magazines, which would bring up that number to 1950 rounds.
- When the player first sees the ACRs in the steam room they have normal gray finish, but when the player picks them up they have black finish on.
- Before Oxide 9 breaches the steam room, two soldiers come out of a small cavern to the left (or right from the breached area)
- When leaving the steam room, one will notice that the civilian cars will be replaced by military vehicles such as jeeps and tanks. They also seem to be going in a different direction. It is highly likely that are under Shadow Company's control, and either they have been alerted by Soap and Price or OpFor have been sighted, since they appear in the next level.
- If the player kills the three/four enemies from their side of the catwalk before proceeding, the additional group of enemies will not spawn after them. This is easily seen when Price says "Move" after all the initial enemies are killed.
- In the explosive-rigged (by Shadow Company) control room at the end of the level, before the player breaches the exit, a table with a map of Shepherd's areas of responsibility can be seen. On the table lie "X"s and "O"s.
- Toward the end of the level, right before the player breaches the control room door, it is impossible to kill the Shadow Company soldier before he closes the door.
- Even though Price says that the enemies are using thermal sights to see through the smoke, the soldiers don't actually have Thermal sights attached on their weapons.
- Although Price tells you to watch his flank, if you use thermal and an enemy flanks you, Price will kill the enemy without saying anything.
- An oddity among the weapons found in this level is a lone RPG-7, the only armament of non-Western origin in Shadow Company's inventory of small arms, which can be picked up after going to a dead-end with a number of other weapons, before the player breaches the door.
- It is possible to find Akimbo Red Dot sight TMP's in the war room, but if the player keeps them for the next mission, they will only have one.
- When the player enters Shepherd's control room, there is a white golf bag. This may be a Dr. Strangelove reference, as General Ripper parallels Shepherd in several ways. First, they both start a war with Russia on their own. Second, they both are somewhat off base when it comes to morality. Third, both keep white golf bags in their offices, although Ripper's had a M1919 Browning in it.
- When the player has to breach the door to access the explosive rigged room, he/she can throw a fragmentation grenade at the door and breach simultaneously, the enemies become alerted and the player is unaffected by its explosion. The grenade will stick to the door.
- When breaching the door, if you still have the Scar-H Thermal Sight with you, one of the soldiers in the room is seen throwing a random gun to another soldier. It is more difficult to see with other guns. When using the thermal scope, it recognizes it as a white color despite not having been touched by the enemy yet.
- Destroying the explosive-laden crates/barrels will result in a message saying "Mission Failed. You shot and destroyed the rigged explosives."
- After Shepherd orders the artillery barrage, Price will say "Since when does Shepherd care about danger close?", a quote also said by Dunn in "Team Player".
- After escaping the cave, if you look back at where the war room is, instead of the whole cave being destroyed, only a few rocks have fallen to block the player from going backwards.
- Even if the player goes ahead of Price before the explosion, the debris will still fall on them.
- Even if the player raises their Riot shield upwards, the debris will still hit them.
- After the artillery strike, there will be Shadow Company troops wounded and on fire. Killing them will extinguish the flames.
- After the artillery strike, there are a few strange oddities that occur:
- The various explosive barrels, power generators and a Jeep haven't been destroyed by the artillery strike, which should be odd as Shepherd had called in an artillery strike that destroyed the whole area, including another Jeep next to the intact one.
- The Little Bird that was firing on you before the strike has crashed, leaving a collapsing frame.
- The SAM site hasn't been destroyed by the strike despite being hit by the strike. If one notices, the affected area begins from leaving the cave to all the way to a watchtower.
- Shooting the two helicopters with the AT4's in the area causes them to crash and explode, although it doesn't cause any leftover remain like the Little Bird.
- The voices of Shadow Company NPCs are noticeably different in quality and style than the voice of other American NPCs in the game. This may be intentional to show the difference between the good and the bad.
- The level's name is a reference to Call of Duty 4: Modern Warfare, as the player controls Soap with Price, as opposed to Roach with Soap.
- Shadow Company uses the same screams and cries as the Militia and the Spetsnaz when shot or injured.
- A number of AT4's can be found embedded in the cave walls after setting off explosions via shooting at barrels or oxygen tanks. They cannot be picked up, even if a player approaches them using the No Clip cheat. The most easily seen one is located right next to other usable weapons placed on a canvas sheet after clearing the catwalk and killing the guards that rappel down.
- Captain Price can be seen using his signature M4A1 w/ M203 Grenade Launcher later on in the level, making a total of four weapons wielded by him, the Intervention, the SCAR-H, the ACR Holographic, and the M4A1.
- Despite being seen, the M4A1 is not usable by the player, a trait shared with the RPD.
- Via noclip, a mounted M249 SAW can be found in this level.