Lets say that he did. Did his oponents throw all his fights after he contracted brights disease? If not that was one hell of a run for a dying man.
First one that came to mind when I saw this thread. Also, Holyfield against Tyson. Holy had been forced to retire after being diagnosed with a debilitating heart ailment, and many people felt he shouldn't even be licensed to fight. Sadly, he's still fighting more than a decade later.