pdq1
As with the other respondents to this thread, I think we'd be jumping ahead of ourselves if we took this chap's word for it that he had no sexual feelings for men prior to the accident.
It may be that in his subconscious, after the accident, he thought, "I could've died?.why bother wasting my life being something that I'm not?"
Incidentally, I find the whole insinuation that the opposite of gay is 'manly rugby player' quite bizarre - especially as both groups spend large amounts of time in the company of naked men, grabbing balls.