Surely Conrad faced him in an aggressive (but not douchy) way, but he provided since the start the proof that Grant was wrong, while Grant was a douche since the start, since his stream, and kept on being so thereafter until the end.
Had he acknowledged his mistake, everything could have been fine, but ignoring the real issue and being a douche he proved he didn't commit just an innocent mistake, but he was lying in bad faith since the start.