It sounds like you frightened him for one thing, but just one more thought, our Max, who we had to let go last month, became a little bit moody and grouchy in the month before we found out he had a tumour on his liver, before he really seemed ill, on reflection I now know that he was experienciong discomfort, and when I would stroke his back he would seem somehow irritated by it, and I think it was all part of the lurking and growing tumour. What i mean is, take him to the vet for a check up just incase he was actually being protective of himeself for health reasons,