To me it didn't look like Kadri intended to deliver a headshot to Backstrom. He was looking towards the point for a tip and, as he said, ran out of real estate. Backstrom was on his knees, at Kadri's elbow height, and Kadri realized at the last moment that a collision was about to occur and braced himself.
If Backstrom is stood up (I'm not blaming him in this situation) and Kadri hits him in the shoulder, a deserved goaltender interference penalty call is made, Backstrom continues in the game and all is fine. But the injury on the play is what is causing this suspension talk, which sucks because it was a complete accident. Much like if two opposing forwards accidentally collided in neutral ice. An unfortunate, unintended injury.
The only way I can see a suspension occurring for the Backstrom hit is a) due to the injury and b) as a message about protecting goaltenders.