I was thinking more along the lines of unenclosed territory, but yes the issue is that this might assume that some end game moves are played which neither player is seeing.
One solution could be to analyze both W to move and B to move and see so that the winner does not change, and if it does, refuse to count and resume the game.
I’d still see it as a viable prevention system for most cases of score cheating and dispute resolution.
Edit: This system is already practically in place through the new anti-stalling system.