Legal or not, this was just a cheap shot by a goon taking advantage of a kicker.
No different than doing this to a QB in the wildcat formation.
Imagine this jerkoff doing this to a guy like Morten Andersen in his 40s.
Seriously, if I were commish, I would insist on 10-on-10 play during special teams. Kickers immediately get off the field after a kick and going 10-on-10.
Kickers, 98% of the time, are not real football players. This goon doing that to Huber was disgraceful. I get that, on occasion, some kickers are actually good tacklers ... but kickers should just kick and leave football to football players.