Feel relieved that you discovered their true character before you actually moved there and joined them and invested time with them. They are probably lying about your performance to have an excuse to rescind the offer --- now you know something about their character. They should have been honest about whatever circumstances changed such that they couldn't hire you anymore.
Yes, that is a good point, and something I see too --- I was just trying to take a shortcut, and say it from the poster's p.o.v., and like usual, my shortcuts backfire.
