Why do they do this 2

[Dan_ref]

A1 drives the baseline, stops in front of B1 and fakes a shot. B1, (about a foot taller), jumps out of his socks and A1 draws big contact as he goes up for the real shot. Easy call, even B1's grandmother in the top row is nodding her head and smiling. As I report the foul coach B is saying "Come on ref, you anticipated that call. You can't give him that!"