It does seem unusual that at his age he has not learned to better communicate. He is avoiding. That is where instead of resolving the differences he prefers to isolate himself and resolve nothing. He is too old for that. This is a situation that can resolved if he is willing. You did nothing wrong. If he had a problem with what happened he should be able to express that and find a solution.
It is very disappointing when you think the relationship is solid and the other person is willing to throw in the towel as soon as a conflict arises. He is not going to adapt your style of resolving conflict and you need to consider that. This is going to be hurtful because he retreats at the sound of conflict. You want to talk. He wants to run.
He may be just overcompensating for the fact that you hurt his feelings. He is allowed this perception. But you can't do anything until he comes to you with his side of the argument and gives you a chance to explain. We don't know if he is the type that can turn off his emotions or just licking his wounds. He could come forward when he has a fresh perspective. Give him a few days.
please press accept; this is the only way I am compensated