DA, very surprised and saddened to read of your experience but of course difficult to comment without seeing the "originals" of the letters you mentioned.
In our neighbourhood, we have a very good relationship with the police who make a point of being very "visible" near the local schools, at start and end of school day.
Flat spin, latest suggestion is that the minibus, which was towing one of those luggage trailers, was completing an overtaking manoeuvre when the rear of the trailer clipped the car that was being overtaken.
Driver had done this trip over a thousand times, according to hotel manager.