That seems really strange. Is there a reason he might have thought you weren't coming? I'm interested about the haven't heard from you bit. Why was he expecting to hear from you? In any case, it seems weird to say something came up and also that he hadn't heard from you. If either excuse was legitimate, I wonder why he mentioned both. Also, why were you asking if he was going to be there? That makes it sound like the appointment wasn't guaranteed in the first place.