He was hurt against Maidana. I think that may have fukked with him mentally as he too quickly goes into survival mode when he's getting hit. Like Joe Louis and Mike Tyson said, "everyone's got a plan until they get hit".
Broner's physical gifts/talents are blown out of proportion to begin with IMO. He's fairly talented when it comes to top level fighters but nothing that stood out to me where I was taken aback. For example, I had very high expectations of Judah in the early 00s because not only was he very fast of hand, but had quick feet, power, and was very fluid in the ring. I thought he was going to be a great.
Broner is fast of hand, but he's not blessed with quick feet or really good defensive reflexes. He's short and stocky which can put him at a disadvantage. I think fighters with fast hands often get overrated when it comes to their potential and their overall skills (Khan was the prime example IMO).