Nothing fishy about it. Silva does this sort of thing all the time. It's something he does to get a mental edge on his opponents and get them suckered into fighting his way. In this case he didn't want Weidman taking him down again, so he tried to appeal to Weidman's ego and get Weidman to punch himself out trying to hit the elusive target. Unfortunately for Silva, Weidman's attack was unorthodox and he zigged when he should have zagged. He may have learned a valuable lesson from this, we shall see.