Fatigue was not recognized as a factor. It was a missed signal that the crew interpreted differently, or during the station stop they did not recall what the previous advance signal would have been, so they were not expecting to take a turn when they did.
There was no mention of fatigue or any other human factors at play, but three people were in the cab, and that was a question mark.
I'd like to clarify that we immediately implemented a procedure that whenever you do a station stop after an advance signal, you must remind each crew member of the last signal before departing that station, and the cab red zone has helped focus vigilance on the upcoming signals by the crews ever since.