It takes 29 seconds to hold the rudder trim in the 737 full over to obtain full trim from neutral. It is hard to believe that even the most incompetent pilot would hold the switch that long in mistaken belief it was a door unlocking button. Even if he operated the aileron trim by mistake it would take about half as long to obtain full aileron trim and that includes pressing two switches together. Something not quite right here. Another case of the automatic monkey syndrome where lack of basic manual flying skills is practically non-existent in many airlines.