There's no standard or foolproof way to find bots, otherwise we'd be able to just ban them all. It all requires judgement. Twitter's statement is acknowledging

There's no standard or foolproof way to find bots, otherwise we'd be able to just ban them all. It all requires judgement. Twitter's statement is acknowledging this fact and legally covering themselves from people just like Musk who might go "well I have my own calculation metric and it says there's more."