Only people defending Warner are people who don't understand the review system.
Firstly, he knew he hit it or he would have called for the review without hesitation. So that alone is unsportsmanlike.
Secondly, during the review because the umpire gave it out there must be CONCLUSIVE proof of a mistake. The slowmo showed no obvious gap between bat and ball. Hotspot was inconsclusive because of the suns glare right where the ball went past the bat.
There was no proof the umpire made a mistake. So it didn't get overturned.
Warner should be ashamed of himself, he knew he hit it.