"This is ridiculous, the crowd's been at the referee and Nigel Owens has now asked for a TMO ruling on a player who's going to be behind the ball and is never, ever in a position to affect the ball," Kafer said in commentary.
"He's been done by the crowd here, Nigel Owens.
"That's shoulder to shoulder, he's behind the ball, there's no such thing as an obstruction.
"Nigel Owens should never referee a Test match again, that is disgraceful.
"He's behind the ball, he can run where he likes.
"It was a crucial decision that absolutely changed the course of this Test match."
Former top referee Jonathan Kaplan and Aussie fans criticised the call on Twitter.