I agree with Wiscoman, except that I wouldn't give him to much space- don't let him feel like he was abandoned or left hangin in the wind- it sounds like he is dealing with some pain of some sort, and just having a hand to hold (no words needed) could help. Just make sure he knows you are still a friend, no matter what happens or happened in this one incident. It might be a good time to initiate some sort of NSA invitation, like to go to a movie or watch a game or whatever.