Audio problem: When Karl is trying to push himself on Jamie, you can hear her screaming when the shot is outside the car, and the screaming continues when the shot's showing both of them, but she isn't screaming.
Audio problem: When Travolta steals the speed boat there is a wide shot of him driving away and you can see Cage running towards him in the top right of the screen. You can hear Cage fire his gun but the muzzle flash doesn't appear until a second later after the gun is fired.
Audio problem: When Castor wakes up from his coma, he reaches up to his face and pulls out the nose plugs that fed him oxygen. Strangely enough, his heart monitor stops beeping when the plug is removed.
Chosen answer: Although they were on the same side, Troy is currently posing as Archer, which means he would have to do everything that the FBI would expect Archer to be doing. The whole point of the raid was to take out Archer, as well as Troy's gang. He would have rather risked killing part of his own gang than risk exposing his identity to anyone else.
Casual Person
That doesn't really make sense. In the scene, he goes out of his way to shoot him and smiles while doing so, carefully and slowly. Was not a collateral damage situation. The question is why he deliberately goes out of his way to kill him.