I'm not even sure the guy isn't a crank, but if he isn't he needs to understand that Wikipedia needs a system that takes cranks into account. If he's simply a false positive on the crank detector because it turns out that everyone else is actually wrong about this historical event then he'd have to demonstrate that the cost of false positives outweigh the good to effect a change, not just go in a huff because his pet subject isn't presented in the way he would like in Wikipedia.