Decided I'd illustrate this:
A: Horton is entering the neutral zone and examining his options, Rome is just ahead of the red line, skating back into defensive position. Ho-hum
B: Horton looks over at his winger option, sees him opening up along the boards. He accelerates a little to the left as he enters the circle to put him more squarely between the 2 Nucks d-men. Rome still chugging along. He's ready to pass. The dotted black line indicates the direction in which Horton's head is turned.
C: At this point, the puck is coming off Horton's stick. He keeps his eye on his winger in preparation to accelerate, making sure he'll be onsides. Rome, meanwhile, is just starting to adjust his stride, away from position (one that will put him between the net and Horton as well as leave him open to cover his side on a dump in) and on a course that will take him across the blue line, towards his partner. The yellow lines indicate Horton's likely field of vision.
D: Horton is just starting his stride and turning his head back towards the middle of the ice. Rome is adjusting himself and is starting his lateral movement.
E: At this point, Horton is probably 2-3 steps into his acceleration. Rome is on roughly his second lateral stride. Rome is just outside of Horton's vision, on his blindside. If Horton notices him at all, it's in his peripheral and he hasn't really figured out what's going on yet. The black lines indicate they're both accelerating.
F: Point where contact begins. At this point, Rome has both adjusted his skating and then made two strong lateral pushes plus another stride or two worth of gliding east-west into Horton's path. Horton has taken 3 strides, in the middle of #4, probably noticing Rome far too late as he enters his vision. Contact is made more or less with the full of Rome's body into Horton's left chest/collar bone area. The green line indicates Rome's overall trajectory during this sequence.
So there are multiple things in play here. Horton is reasonably safe; he assessed Rome's position, looked over to make his pass, kept his head up a moment to check onsides. In that moment, Rome slid into his blindside and began to adjust his own stride. Horton glides a couple steps' worth at this point, then begins to accelerate as he begins to turn his head back. At this point, he figures he's safe as he's already glided a couple strides worth after his pass, Rome wasn't close enough to make contact at this point. Horton begins to accelerate forwards as his vision returns to the middle of the ice, but doesn't notice Rome as Rome is fully in his blindside at this point. Rome's lateral steps begin not only after the puck has left Horton's stick, but after Horton's glided a little. Their accelerations begin at roughly the same point. By the time they make contact, Horton has made 3 to 4 accelerating strides and Rome has made an adjustment, 2 lateral strides and another 1-2 strides worth of gliding as he braces for the hit, moving fully east-west by the time of contact.
Ultimately, Rome creeps into Horton's blindside and begins to accelerate towards Horton well after the puck is off Horton's stick. Horton begins to accelerate, the puck at his winger by now and Rome is just beginning his own stride at that point. He has another stride or two plus a little more distance worth of gliding to decide to ease up on the hit, though he's already put himself in a stride that will bring him out of position. Probably subconsciously realizing he's already begun to take himself out of position, he continues accelerating towards Horton even though Horton has traversed most of the Canucks half of the neutral zone since releasing the puck. Even though Horton's vision returns, at this point Rome is well into his blindside and Horton doesn't likely see him until it's too late to do anything. Not only does Rome not back off the hit, but he even puts follow through into it.
This play contains:
1. East-west blindside hit, though it wasn't targeting the head, it was a blindside that caused injury.
2. Extremely late, not enough so to be totally away from the play but well after the puck is gone from Horton.
3. Possible charging, as Rome accelerates laterally into the hit and towards Horton. There's no doubt he did so with intent of violent contact.
4. Possible headhunting, or at least very stupid decision making, as Rome put himself out of position to make this hit and followed through either because he realized he'd put himself in a dumb spot, or because his intent was to demolish Horton.
5. Resulting injury. Unbraced contact at high speed, the very likely concussion was probably sustained at impact due to the sudden G force acceleration and whiplash, rather than when he hit the ice (he was probably already out by that point). Doesn't really help matters with the above 4 conditions.
All of this adds up to a long suspension. I think the NHL got it right.
If some bored artist wants to make me a signature, feel free to cut loose and do so.
Of course, I could get off my lame rear and do something.