This seems a perfect candidate to test with some well known test games.

Fischer's 17 ... Be6, for example in the Game of the Century

Or 15 ...Nf2 (again Fischer and Byrne) http://www.chessgames.com/perl/chessgame?gid=1008419&kpage=1

It might be interesting to see how many blunders this identifies compared with traditional analysis. (Looking at the "surprising bad move" vs "surprising good move")

In any case, very interesting work. Others have some good ideas for additional checks/considerations, and it would be interesting to see how this evolves!