I have not seen any freesync projectors around. I imagine they could have recorded game footage and play it. But then everyone would be like... And maybe they played it from recording, but then man in the middle attack happens in form of DP/HDMI/... switching device which is connected before projector, so they can seamlessly change sources. There are many possible causes for image tearing in such setups. But since none of them is applicable to regular gaming setup: GPU => Cable => Freesync screen I can't care less.