RAIB Report: Trap & Drag at Notting Hill Gate

You have completely missed the point.
The passenger might be blamed for getting trapped in the doors. The passenger is in no way responsible for what happened after that, regardless of whose fault being trapped was. As long as there are both doors and passengers, passengers will get trapped in doors (deliberately or accidentally) unless there is some person or device that physically prevents a person entering or leaving once the door closure warning starts and ensures that all body parts and items of clothing and luggage are free of the doors, and this would be required at every doorway that can open (even if they usually don't) at every station or other place where passengers may board or alight. This is obviously not practical. Therefore the railway must instead ensure that when a passenger gets trapped in the doors they are not dragged - there may be actions the passenger can do to assist with this, but unless every passenger is given a training course on what to do in the event they are trapped or see someone else trapped and required to pass a test to show they have learned it before they are allowed to board, then the responsibility lies entirely with the railway.