He might have been distracted or in a hurry, or something entirely unrelated to you might have been bothering him...lots of reasons for a shorter reply, or there might not be any negative reason at all. I truly understand the panicking over small things like that because I do the same thing, but from an outsider's perspective, I really do not think he's annoyed with you at all. You are important enough, and I'm sure he will do as he promised. Let us know how it goes