> Then, going through their code, they make excuses about their code not meeting the same standards they demand.

Yes!! Exactly. When it comes to my PRs, he once made this snarky comment about him having high expectations in terms of code quality. When it comes to his PRs, he does the things he tells me not to do. In fact, I once sent him a "dis u?" with a link to his own code, as a response to something he told me I shouldn't do. To his credit he didn't make excuses, he responded "I could've done better there, agreed".

In general he's not bad, but his nitpicking is bad. I don't really understand what's going on in his mind that drives this behavior, it's weird.