For mine there was nothing wrong with either Ziebell's or Gibson's hits.
It's a contact sport, players get hurt.
It's the inconsistency from round to round which is infuriating.
I dont see anything wrong with JZ's hit as he was attacking the ball carrier with intentions of affecting the disposal.
The Gibbo one is slightly different for mine, as i have always said the man on the mark should be protected at all times. Blocking, shepherding even touching the man on the mark should be outlawed imo.