He's even worse than a sore loser, he's a sore winner! Xeon might still be the better fisher - he's figured out a really useful and repeatable technique that demonstrates some really deep knowledge of gloomfish. While Terra's method is a brilliant solution, it's also brute force and has the limitation of only working once.
But Xeon was competing to put uppity women in their place and publicly humiliate them. It's that need to humiliate them that dug his own grave here - by broadcasting it to the world he can't obviously take advantage of his winning position to further humiliate them behind the scenes. He wasn't validated by the contest results he wanted, and he's throwing a tantrum over it.