Humans are not so logical. They are also known to be much worse than they think at reporting their own experiences[1], and prone to shared delusions, especially under stress[2]. There are always wild rumors under circumstances where reliable information is scarce[3].

1: https://www.scientificamerican.com/article/do-the-eyes-have-... 2: https://en.m.wikipedia.org/wiki/Mass_psychogenic_illness#In_... 3: https://en.m.wikipedia.org/wiki/Lenin_was_a_mushroom