Impossible to prove? He's took FLUSH HEADKICKS from MIRKO CROCOP! Mirko's HK > Any Boxers punch in history.
Hunt RAN into that punch. And Melvin hits HARD AS ****. Name me TEN BOXERS who could EAT HEADKICKS FROM MIRKO CROCOP (in his prime) and not be knocked out. You think taking a punch is in any way comparable to taking a head kick?
The sad thing is, compared to most 'elite' boxers, MMA fighters duck nobody and you have to earn your straps instead of protecting the 0.:deal