Fake it til’ you - have to quit out of fear of legal repercussions.
At a former startup I interviewed someone for what was supposed to be a plain old individual contributor developer role, and the suit seated across from me was clearly interested in the newly opened VP of Eng. role.
I never bothered chasing down if it was a scheduling mixup on our chaotic startup side, or if he was just trying to get his foot in the door after somehow hearing about the newly opened executive vacancy. Either way the technical interview went so badly he stormed out of the office in a rage.
Point being, mixups happen all the time. It's not hard to imagine scenarios where it still results in a hire, and seems difficult to place 100% blame without a recorded confession or something. It's clearly the potential employer in the driver's seat, caveat emptor of sorts applies.