I don't mind him being salty over the sideline interviews; they're interfering with him doing his job at its most important point, and the questions are generally pretty dumb just by the nature of the thing. Pop's crankiness makes them much more entertaining then they usually are, and the pros have learned how to work with Pop; see Doris Burke last night or Sager most nights.
But the jab at the press conference was pretty crappy I thought; the reporter's obviously not trying to coach, he's trying to get a coach's opinion on whether he thought an approach that worked fairly well maybe could've been implemented sooner. Pop just seemed to take it personally, probably because it hit closer to home than the reporter intended. He knows the first 3 quarters were a failure from a coaching perspective and bristled at a question that he read as implying that.