It's not a fair question to ask in hindsight.

At the time of the fight, anyone who said that he quit were perfectly justified in saying so, because no-one, not even Dubois himself knew what the problem was.

In hindsight, he did the right thing, but it doesn't alter the fact that he did quit.

Hopefully he can recover fully & resume his career, because he seems really dedicated to the sport & comes across as a decent guy.