I See (Nearly) Dead People: The NHL's Head Shot Criteria

The Blackhawks' Duncan Keith apparently will not be considered a candidate for suspension for his hit to the head on Matt Cooke... who incidentally was playing in his first game after serving a suspension for a hit to the head on the Rangers' Artem Anisimov.

Hockey Plumber has discussed this topic before.  The NHL clearly does not tolerate knee on knee hits as witnessed by the time outs dished to Georges Laraque and even superstar Alex Ovechkin. Yet, as the list of 2009 NHL suspensions grows, we fail to see any consistency.

Note that this hit DOES merit suspension:



This hit DOES NOT:



and we STILL cannot believe that this hit DOES NOT:



So what criteria does Colin Campbell use to determine if a shot to the head deserves consideration for suspension?  A dart board? His mood?  It's not the extent of the injury, because as seen in the last video David Booth is still out from the hit by Mike Richards which occurred on October 24th; and Anisimov played in the Rangers next game.  Does Campbell possess a sixth sense that can measure the perpetrator’s intent?