You knew it wouldn’t take long before the new “head-shots rule” would come under scrutiny because of the leeway officials have in enforcing it.

Last night, San Jose center Joe Thornton was ejected for his hit on St. Louis’ David Perron and it sounds like the league is considering a suspension for the Sharks captain.

Here’s a look at the play from multiple angles:

Now, I’m all for the “head-shots rule” and the reduction of blows to the head in the league, but this one is so borderline you have to wonder if NHL on-ice officials (or any humans) are equipped to make such a spur-of-the-moment call at the high rate of speed of the game. In fact, it might be time to let a television screen or the boys in the “War Room” help out with these calls.

Thornton’s hit was certainly a blow to the head. But it’s clearly shoulder-to-head contact, which is legal under the new rule as long as the hit comes from the front. Was this hit lateral or from the blindside? To me, the fact that Thornton exited the penalty box and the hit occurred toward the St. Louis blue line proves he was going at Perron from the front. I hate to criticize the victim, but Perron misses the pass and fails to turn his head, not to mention he obviously wasn’t aware Thornton was about to get out of the box.

Now there are two aspects of this play and the punishment that serve as a cautionary tale for Bruins players and players throughout the league. It starts with the fact that the officials, knowing how much the league wants to take head-shots out of the game, are seemingly going to be sensitive and lean toward doling out punishment any time a player is hit in the head and goes down. It seems the attitude is it’s better to call the penalty, hand out the game misconduct and then apologize for it afterward if it wasn’t warranted rather than risk not penalizing a player for a vicious hit that violates the new rule.

That in itself establishes a fine line that could cause some of the league’s best players to not perform at their peak, and could take some of the sport’s most exciting plays out of the mix.

The other troubling part of the call on Thornton, is that this is obviously a hit to the head as a result of Thornton being 6-foot-4 and Perron standing just 6-0. Even long before the adoption of  the new “head-shot rule,” commissioner Gary Bettman always brought up the scenario of Bruins 6-9 defenseman Zdeno Chara practically having to hit every guy in the head — just based on size alone — when explaining how difficult it is to define an illegal hit to the head. Let’s face it, “genteel giant” Joe Thornton wasn’t aiming for Perron’s noggin, but the Blues forward got hit in the head because that’s how the hit lined up.

The Sharks lost 2-0 (Perron returned to the game to score one of the goals) and missed their top offensive playmaker desperately. Could the Bruins find themselves down their captain and best power-play point man in a future game should an opposing puck-carrier wind up connecting his head to Chara’s person in a play that causes officials to overreact based on the new rule? As long as the four officials on the ice are left to determine what constitutes “lateral” just by watching the play once at full speed, taller players everywhere are at risk of unwarranted penalties. When the league’s GMs sit down this weekend to discuss expansion of the replay rule, this is one they might want to take a closer look at.