When Pokemon Emerald was revealed, and the Frontier was shown in scans, Serebii insisted at great length that the Frontier was actually the game incorporating the anime's version of contests. This was despite the fact that the text was right there and people were telling him he was wrong. He accused them of going off inaccurate and doctored scans and only he had the real copy. Then he kind of quietly pretended like none of that happened.
Let's see. He claimed you could trigger the Arceus event (Hall of Origins) multiple times without hacking, which wasn't true. He made up numbers for the honey tree percentages, then went back and changed it when called out, without admitting the originals were phony. He's admitted to news theft, but only in the instances the news was fake. When he steals and it turns out to be true, he claims he was the original source.
He very rarely checks his sources, in any event. I'm just saying, he's fairly unreliable by any non-Pokemon fansite standards.