I once caught someone lying on a resume, but only because they mentioned a former employer that was also my former employer and while they worked there, they didn't work on the project they claimed (which I had worked on, it was a small team, and which happened before they got hired there.)

But that was a lucky catch in a relatively small town.

How did you decide not to move forward with a candidate? Are you sure you didn't make a decision based on uncorroborated data? (EG: One can say whatever one wants about someone online, and when you google their name it may come up, even though the source has an axe to grind.)