Jon is throwing multiple darts into the bulls-eye, when it cuts to the dart board it shows about 9 darts are sticking out of the center of the board, in the very next cut, which shows Jons arm in the after-throw position, there are no darts on the board at all... not even one. Yet the guys playing pool look at him with astonishment, maybe because he was able to make the darts disappear...
When Brent is shouting in the hallway for Morris to come out and face him, the scratches on his neck are already visible, well before he gets clawed at super speed.