The video you included is part two, starting in Plettenberg. Part one can easily be found by stopping the video and following the link youtube provides. In that part you can see the train using the opposite track (from running time 8:10 til the stop at Hohenlimburg) because of the safety precautions required by the track construction. At around 16:35 there's a passenger announcement which is hardly understandable. They are being told that the train gets split at Lethmathe and that the rear part will go to Iserlohn. At 23:50 you'll see an automated emergency stop, and afterwards the driver informs the passengers they needn't worry. If there's anything else someone would like to have translated, just let me know.
