Pure speculation on my part but here's my guess.
He's already been told by Bowden in the past to shape up and throw strikes or he was off to minors. My guess is that he had yet another talking to regarding his abysmal performance last Saturday. After walking in that run, I suspect whatever they threatened him with will shortly come to pass hence the temper tantrum.
What temper tantrum. I just tuned in at the top of the 4th.