If there is no notice of disapproval in their file in OKC their logbook is really the only record of a redo. A bad wx day or broken airplane could also be used to explain a lot of those odd logbook entries. Stage checks were a little overdone at my previous 141 school and I think there would have been almost 20 checks all the way through a multi engine ride. It is ultimately up to the airlines to define what they view as a "failure" and they all do have very specific instructions. As I recall American and FedEx both broke up EOC rides separately from the letters of disapproval.