Keith did initiate that contact and no he shouldn't get into trouble for it and neither should Lynch, which is why it was thrown out. Lynch had no case to answer.
There IS a rule that if you duck your head seeking head high contact, it's play on. It would help a lot if that rule was consistently applied, every time. The umpire needs to yell "keep your head up!". It wouldn't take long to stop it.
Joel Selwood is the only player in AFL history to have received over 1000 free kicks in his career. I'd estimate half of them were from drawing those free kicks by leading with his head or shrugging his shoulders or dropping his knees to make the tackle slip high. (Many of those times you see the tackler complain to the umpire, before that was banned, that Selwood was playing for a free by using his head). We all saw it for 15 years.
If the umpires didn't pay those free kicks others wouldn't do it, it wouldn't be an incentive to kids coming into the game, the media might have stopped blowing hot air up his ass for being some kind of hero (I admit he was a terrific player) and he wouldn't carry the nickname Duckwood to his grave.
If Selwood has problems later in life like Danny Frawley or Shane Tuck (and I certainly hope he doesn't) who will be to blame for that ?