The flip side of this is don't believe everything you hear... I used to fly with flight attendants all the time who swore up and down that they had bed bugs at X Y or Z hotel. If you asked them how they knew, it was either "I woke up with a bite" or "I just knew".
Moral of the story, check your bed and don't worry about what others sat about a given hotel unless they have proof. (i.e. Pics or it didn't happen)