You're saying "it stands to reason that a widely used product would have already hit this corner case by now." The problem with your argument is that it's a tautology. If in fact the statement by dcurtis is the first efflorescence of the problem, your line of thinking would reject it anyway.
That's why it's useless to say "this feels wrong" or even "surely we would know by now." The guy who wrote the tweet has already said here in HN comments that he will substantiate what he wrote, so it seems unnecessary to dogpile the skepticism and "feelings" in the interim.
You don't have to accept a logical proposition in order to consider/entertain it.