In these situations it is far too easy for one person or any number of people to get hurt emotionally, it's a risk.

In this case have you tried to get in contact with him? If so and you got nothing has this ever happened before.

You have to remember he is married and that relationship will always come first for him, the anniversary trip might have bonded him and his wife once more that he might have felt guilty. It's hard to say really since anything could have happened. He might be swamped with work and has simply not contacted you.

Knowing what you know about him it's best for you to make the judgement you think is best.