I also don't feel the article was trying to accuse the author. That said, their quoting of "crucial mistake" when contacting the author makes it look like they are doubting it was actually a mistake, indirectly suggesting that they suspect some kind of misconduct.

I think they actually quoted the term because that's the correct grammatical rule, at least from my memories of school. Still, the practice is so often used by accusatory journalism that it now makes the usage look suspicious.