Do you think my boss is upto something else?

He is obviously stressed about something and probably feels that small slip-ups are a sign of bigger slip ups that he may not be being told about. It makes him uncomfortable and he is probably concerned that you and he may not be on the same page. Perhaps you could do an end of day summary for him on email simply stating what came up and very briefly, how you handled it. If there is something of greater magnitude, go to him for his advice before you act otherwise you may be fingered for something that either you didn't do or something that was simply handled in a manner inconsistent with his way.