This is one of those things where everyone will instinctively want to say "No way that could happen, everyone I know is super responsible and always makes sure the hash cakes are carefully labelled", but that presumes so much. Not just that the people she was with were responsible, but also that she didn't, I dunno, totally ignore a bunch of warnings or something.
Reality is, people do dumb shit. Any argument that depends on that not being true doesn't pass the sniff test.