“It is important to note that Greer is in control of this play at all times. First, he hooks Zary enough to cause him to lose his balance slightly. Then, as Zary regains his balance, and at a dangerous distance from the boards, Greer delivers a shove to the upper back of Zary that knocks him to the ice and causes an impact with the wall sufficient for supplemental discipline. If Greer wishes to initiate contact on this play, he must do so in a legal fashion rather than shoving Zary in a way that causes such an impact.”