So steelmanning the cold fusion crackpot's argument may have brought you to firmly believe in cold fusion, that's fine as long as you don't forget that the crackpot still believes in the right conclusion for the wrong reasons (the weak form of the argument), and is as such still a crackpot.

Of course, if you're finding that someone seems to repeatedly arrive at the right conclusion for "the wrong reasons" you should take this as evidence that said reasons are better than you thought.