[sokoloff]

It’s also possible for the flight crew to have been fighting the AP (often inadvertently), resulting in auto-trim continuing to trim against them.

If the crew applies sustained pitch up inputs, above what the flight director is commanding, the auto-trim will apply trim down to compensate. This can result in pilot applying even more pitch up input, resulting in more trim down. Solution of course is to kill the AP and trim motors, the multiple means of how to do so is a memory item in every aircraft.

Trim runaway has caused accidents to be sure, but is still a flight crew error IMO, unless every means to kill the trim was tried and failed.