Indiana Jones and the whole day field walking what locals assured him was a very promising site, with the only finds being 5 modern nails, and a pop can ring pull😉
(Sorry, I remember whole Time Team episodes like this.)

Normally a red flag that they wouldn't recognise the truth, if it tap danced on their testicles in hobnailed boots, are really seeking confirmation of their preconceived notions, and will denounce anyone who dares to present evidence to the contrary.