Why isn't he communicating?

Seems to me like he is just being over sensitive. If it was so important to take you out to dinner, he should have called or at least texted. He would have had a better chance of contacting you in time. All I can see is, if he is acting that way, he will either get over it, or he won't. The question is, if he doesn't get over it, do you want to put up with it?