I've been thinking about this, always a dangerous thing
They say the trailer overtook the car suggesting it was a downhill stretch of road, therefore no drag on the towbar. If the trailer brakes were not working well the trailer could actually have been pushing the car. Interesting time for a towbar to fail was all I was thinking.
Also got to thinking about whether breakaway cables work if the trailer somehow is in front of the attachment point rather than pulling back on it. Will be checking my Ifor next time I remember
Also how was it loaded, mine has enough nose weight to mean the front would drop if it came unhitched, not overtake the Landy
Always thinking of stuff to make towing mine safer