From the NHL rulebook:
61.1 Slashing - Slashing is the act of a player swinging his stick at an opponent, whether contact is made or not. Non-aggressive stick contact to the pant or front of the shin pads, should not be penalized as slashing. Any forceful or powerful chop with the stick on an opponent’s body, the opponent’s stick, or on or near the opponent’s hands that, in the judgment of the Referee, is not an attempt to play the puck, shall be penalized as slashing.
From my interpretations of the rule above, slashing seems somewhat subjective - it depends on whether the referee feels that a player was attempting to play the puck.
Assuming that a player is playing the puck, will hockey referees ignore any contact to an opponent, even if the chop is aggressive or forceful? How much does the rule's intent to reduce injury risk affect these types of calls?