Yes, MR does mess up from time to time. But it also takes them a while to catch their errors. I had a missing stay back in June. Went back and forth with MR and the hotel, but finally posted with a duplicate posting for an earlier stay. One night and less than 1K points, no big deal. Come August, they pulled it. I'm over 100 nights this year, so it's not gonna make dent in my status.

Moral of the story, YMMV and not wise to post post their mistakes on an open forum.