Note that the claim is not that it's an ELO 1400 human equivalent player but that it can play chess at a level that gives it an ELO of 1400, which is not nitpic

Note that the claim is not that it's an ELO 1400 human equivalent player but that it can play chess at a level that gives it an ELO of 1400, which is not nitpicking: that's a completely different thing. We're not testing whether it plays like a player with ELO x, we're proving that "it can't play chess" is fallacious. It can, and when prompted properly, it can achieve an ELO of 1400. ELO allows for illegal moves: as per the rules of chess, you lose the game if you make an illegal move. The end, ELO doesn't care about why you lost a game on purpose.