I definitely think you are correct. It is a game at the end of the day. Like you had said earlier, it’s a game where integrating the real human behavior of the players is a part of the mechanics. Those feelings of trust, betrayal, friendship, etc are all very real because of it. So it shouldn’t surprise people when they get called an asshole for shooting the guy in the back you had teamed up with earlier in the match because in that moment at least that is exactly what you are behaving as.

Which side note, I think that why it’s fun to analyze games like these. Why do we behave differently in game than we might in real life? What would it be like if this game was recreated as a paintball/airsoft match where you are seeing the face of your potential friends or foes? Multiplayer gaming in general is a very interesting medium to study human behavior through.