*Spoiler* I don't understand why...
Towards the end of the movie, after the kid refuses to shoot the soldier, why did he decide so quickly to kill the man who was trying to murder the soldier? Throughout the movie he has a couple of opportunities to kill Gary Hook but judging by his reaction he's physically unable to kill anyone. Then he coolly shoots another man just before the end. Maybe I'm missing something here but this just didn't make any sense to me.
Great film other than that. Wasn't a fan of the shaky cam but it's a great concept and an enthralling story. Fantastic performance from Jack O'Connell as well.