It's hard to understand, Joao, how thoroughly you've missed the point despite it being stated so many times. This guy was a mediocrity and a jerk.
EVERYTHING he did was half-assed, from his English to his code to his communication. He was unsurprisingly the only person on the project who emailed every commit he did to everyone else, even the ones that were completely inconsequential, like changing a comment.
And he was a jerk. When he rewrote that API he did not communicate the changes to anyone, even knowing that there was probably code that checked the returned HTTP status and branched accordingly. And when I asked him—repeatedly—why he had changed them he didn't bother to answer.
And there was something wrong with his mind. When he asked about the branch name that he himself had spoken only moments before it was like advanced senility.
If this company called me back for more work I would only accept on the condition that I did not have to work with this asshole.