I do not think the hit was malicious on Reeves's part whatsoever. But Hronek's head was a principal point of contact. Incidental? 100%, no doubt. But I can see why people don't like the hit.
Hronek 100% has to be more aware as well.
It could very well be a suspendable hit based on the contact to the head. But with how inconsistent the league is, who knows? I wouldn't be upset either way. If no punishment, it was just an unfortunate result. If he is suspended, rules are rules, accidents be damned.