Easy there Charles Lindbergh, I’m sure they were trying to trim. But in the 737 (maybe other aircraft), if you are applying significant force on the yoke in the opposite direction of the trimmed condition (ie nose down trim and pulling back very hard on the yoke), the trim wheel is very difficult, if not impossible to move without releasing the back pressure in this instance. I’ve flown a variety of aircraft in my life, and I’m not aware of any other aircraft to which releasing the pressure on the yoke/stick was a requirement to move the trim. I suppose if you’ve flown the 737 you’re entire life, you’d be aware of it. But its not instinctual or natural. And maybe they thought that putting the AP on would help the out-of-trim situation, as it has its own servo. JMO