He's never warned because Vegas stands to much to much to lose in revenue if his aura of invincibility gets debunked. If he gets knocked out in spectacular fashion and its shattered, they milk the rematch and then start building the next one. If it just gets dented by him getting outworked, people start losing interest and stop buying tickets which means less people show up spend money staying in the hotels, gambling in the casinos and other attractions up and down the strip.

Taking the elbows and forearms away from him, means a guy can just lean on him and grind/ maul away while racking up points. The refs see it, just as many an opponent has pointed it out before during and maybe even after a fight over the years so its not as if noone sees it or knows its there. Being the star attraction affords him leniency because it keeps the money machine rolling. Just as it did for boxing before he fought exclusively in Vegas and he was building his brand. Just like Tyson used to get away rocking someone with a forearm here or there or oscar got away with holding oba carr behind the head and punching...