Fighting in hockey goes back to when the game began. Emotions run high and it provides players with a tool to police themselves if the game gets out of hand. With that choice of fighting also comes some inherent risks, but players who engage understand those risks.
As two players drop the gloves and are prepared to engage a linesman makes a very irresponsible decision. Rather than circling the two combatants the linesman cuts directly between the two. This choice leaves one player completely blind to the impending right hand and as he steps forward he eats a shot directly to the button. The left hand sends him directly to the ice.