Byrd fought Golota and Tua even ... He beat McCline, he beat Cooper, he beat dangerous guys like Purity and Williamson, yes Evander was old but he beat him easily . Considering he was a blown up super middleweight he did very well ... In his prime at heavyweight who beat him but Wlad and Ike who despite your revisionism may have been the best heavyweight on the planet at the time ... Byrd was a terrific fighter.
We'll never know for sure it's all just assumptions on both of our parts but we do know the injury occurred during the fight and not prior to it. So we can assume Byrd making Vitali miss and punch at awkward angles may of instigated the injury. Regardless as I said Vitali had all the advantages in the fight and didn't walk away with the W so as I said tough luck. If he felt the win was a fluke he should've rematched Byrd but he never did or even tried to make the fight happen to my knowledge.