The concern last Thursday would be that the umpire probably would have called Maynard’s smother and collision “intentional” given he immediately reported him and paid a downfield free kick.For mine, the send-off rule would work fine for clearly "intentional" acts where a player is concussed / injured etc
But i would have classified Jack Martin's hit on Blakey as intentional ..ball has all but gone, clenched fist, swinging arm, belts him in the jaw. The only reason he doesn't break his jaw is Martin's small bony hand /knuckles. Grading that as 'careless' is a joke .. he lines him up with intent, it's intentional in my eyes.
That’s the tough thing about a send-off rule. No doubt there would be some controversial instances.