For starters, that writer is an idiot. It wasn't late and he didn't leave his feet before contact. Part of the reason the hit was so vicious is Sobotka was still following through on his shot and couldn't protect himself. People need to stop watching gifs and slow motion replays and actually watch the video at regular speed.
I don't know about international standards but by NHL rules the only issue is the strides he took before the hit. That could make it charging. To me it looks like he's hustling back to make a play then veers into the hit, but it gave him a whole lot of momentum and made this hit a nasty one.
As for the rest, he does contact the head but he makes solid contact through the body. That's legal in the NHL because of the solid body contact (I don't know about international rules). He doesn't leave his feet before contact.
If Sobotka gets up, it's likely nothing happens here. Even if it were in the NHL though, because Sobotka doesn't get up it's likely getting a suspension.