It doesn't matter if he NEVER said it or if it was never mentioned in a FOB. Doesn't matter. Just because someone caught the mistake and asked a question in FOB times doesn't mean jack, that was the purpose of the FOBs, for fans to ask questions and point out mistakes. Just because the FOB are not canon doesn't change the fact it was an error in continuity.
It isn't cherry picking anything. It is noticing that FO 2 had a mistake.
MCA is also not the authority on WILD FEV. He didn't create it. That was Taylor, Cain, Anderson, etc. Not MCA. Now, if Chris Taylor wrote the bibles and made that statement, maybe you have a point, but MCA didn't work on FO 1, and he didn't create Wild FEV.
Using YOUR logic, there could never, ever, be a mistake in game, because it all just is. How convenient that now BGS will become "perfection" and everything they do immune to scrutiny. That isn't how it works. They made a mistake in FO 2, it pointed out. They made a mistake in FO 4. It pointed out.