I'm not sure that's the smoking gun.

IIRC, there was some "konami" code to re-enable the train after disablement that was removed in a first-party update after the third-party repair company found the sequence.

And not related to the third-party locations, one of the trains had some code where if the year>2021 & month>11 & day>? then the train would disable itself; ultimately doing it in the wrong year because the train was off during november / december of that year. This is a little excessive for somebody random to do.