I have no idea why this agent acted like an idiot. But if the agent say to the press something to the effect that they won't extend KP during the season but they will do a drive by hit on Penn . . . if he didn't realize what the press, and particularly Canzano, would do with that, then he isn't very savy. I think this agent was pissed and trying to take shots at the organization including using KP.
I don't see what the big deal is. I am pretty sure with the timing of this that Penn had been out fishing for GM level jobs elsewhere and got caught doing it. That is not a very smart thing to do when a billionaire had gone out of his way to give you a huge raise and title to retain you recently. When those people find out that despite their effort to retain your loyalty you are out fishing for the Clippers GM job, that tends to not go over to well. You might as well send Paul Allen a letter saying "I don't want to be here."