I was in this sort of circumstance on a SEPTA train (using the same rails and stations as Amtrak fwiw) and they let us walk to the next station with no pretext. It was just the common sense thing to do and the SEPTA personnel running that train felt empowered to exercise common sense.

The more bureaucratic an organization becomes, the more inhuman it becomes. An unwillingness to bend rules when the circumstance rationally calls for it is extremely dangerous. One might think that Germans in particular would be highly tuned to this problem, but no. They still put following orders first. Typical.