Brady's sideline blow ups are well documented. He has always appeared to be a difficult teammate. He blew up at coaches a well. When things didn't go right he devolved into a whiny brat.
But this is not new. We've all known this for forever. He is a douche, but he was a great QB and competitor. Those things sometimes go hand in hand, for some reason. There have been a lot of jerk control freaks at QB.