While I don't see anything wrong with needing to check in with his wife to make sure she didn't make plans for him, I do believe that his approach with you was rude. He should have gotten back to you right away.
Runic Wolf's mother will often make plans with one of us and we expect that the other one was informed as well. Only to realize that we suddenly have "last minute" plans to do something with her, either because she forgot to tell one of us or she expected our son to. Because Runic Wolf does alot of "yes, mom"ing in conversation, he often agrees to stuff without really hearing what it is. So it is important that he or I check in with each other before making outside plans. However, if plans need to change, we tell whoever it is we have plans with, as soon as we find out. It sounds like you need to explain to him that you expect the same courtesy.