From Halopedia, the Halo wiki
From Halopedia, the Halo wiki
Throughout the Halo series, there are numerous glitches that take place during cinematic moments that affect certain parts of them or change them completely. These glitches happen when certain objects or even A.I.'s are introduced intentionally or not into the cutscene.
Before the cutscene begins, lure a Hunter from the Shuttle Bay to the Brig then activate the cutscene. The Hunter will not be frozen and will reach to the characters that participate in the cutscene, knocking the Master Chief around, killing Captain Keyes and shooting at the Marines. Once the cutscene ends, the Hunter will still be there and the player will have to fight it to proceed with the mission. Another thing that can happen is if you throw a grenade just as the cutscene begins, you will die, the cutscene will only play for a few seconds and when it ends, you will spawn dead, looking at your own body and not being able to do anything. There is no way to continue the mission from that point.
Once you reach the closed door that leads to the Cartographer, park your Warthog with the Marines inside, then proceed on-foot towards the second structure that unlock that door. Once you trigger the cutscene, the Marines in the warthog will start to fire on the Zealot that comes out, and it will also react and try to kill the Marines.
There are a number of things that can happen. You can lure a Hunter inside and it will try to kill the Master Chief, knocking him forward, shooting at him and sometimes even knocking him inside the huge pit in the middle of the room. Another thing that can happen is a Banshee can follow the player inside the corridors and once the cutscene plays, it will splatter the Master Chief, fly around the room and even act hostile towards Cortana.
If the player pushes the Shade turret in the way of Jenkins's scripted walk path prior to entering structure beforehand, he will get stuck in the spot where the turret was placed but continue his scripted movement while the rest of the squad moves ahead of him into the structure due to the fact that the recording takes place in the exact same places that the player previously traveled. This is because the game doesn't "clear out" the room and return it to the state that it would be in when Jenkins and his companions were in it.
During the final cutscene, the player can bring a Banshee inside the room and park it where the Master Chief's speech is going to happen. When the cutscene is triggered, the Master Chief will face away from the Pulse Generator and the Banshee will also be present in between him and the Generator.
During the cutscene where the Master Chief goes into the Gravity Lift, if Flood Combat Forms are still alive in the area, they will attack the Chief then back away, and if Flood Infection Forms are still alive, they will latch onto the Chief and he will start to spew up blood.
During the cutscene, if Flood Combat Forms are still alive in the area and the cutscene is triggered, they will attacks the player, knocking him down from the pedestal. The Proto Gravemind's face will then seem to explode at the moment where the Master Chief should have punched it. If the Flood has no arms then it will just stay close to the Master Chief during the cutscene. Also, if the player manages to lure a Hunter into the room, it will push the Master Chief around, even killing him. The cutscene will take place like with the Flood inside.