This is an example of one of the major problems of crowd-sourcing: trust. There is no way to verify that the integrity of the submitter, who could be giving wrong information due to malice, incompetence, or as a prank. There's entirely too much trust in crowdsourcing.
Sure, it's unfortunate, and these kind of "crowd-sourcing casualties" are going to happen here and there, but is it really that big of a problem, relative to the value that is gained?