I punched through a dozen or so and 100% of those were rhetorical. You need to combine it with some NLP like Kevin's doing here: http://reviewsignal.com/webhosting/
I had a lot of rhetorical questions too. Also, Kevin's solution is not 100% waterproof - just looked through some "negative reviews" for ServInt and they weren't exactly negative. Maybe you could build a bayesian filter of some kind? (I'm not sure how Kevin filtered his reviews exactly?)
That said, if you see mistakes, please flag them! My system does get smarter with more data, so when people flag mistakes for us to correct, it makes a difference both immediately and in the long run.
If you have any other thoughts/critiques/ideas please feel free to let me know :)