It would have been nice.

That said, I think that last scene between Colin and Ephram was very layered. I will always believe Colin was indirectly giving his blessing to Ephram for being with Amy in the future. I think that was going on big time so an apology might have been weird. But then again, it actually would have been nice seeing Colin apologize for beating him up at the same time Ephram was attempting to say he was sorry for what was going on with Amy. If you look at that scene and read the words and nonverbal communication, Ephram was slightly trying to apologize and Colin stopped him. There was a lot going on in that scene for sure. Colin apologizing to Ephram in a prior scene and then having the final scene remain the same would have worked though.