The trim is just a micro adjustment to compensate for cross winds so the pilot doesn’t have to constantly adjust the controls to maintain a constant heading.
I don’t know if the plane used hydraulic, cables or what. If it is cables, a snapped cable could wrap around, jam, or freeze controls.
I’m just guessing. Usually something like this isn’t caused by one thing but several failures (Murphy’s Law).
The trim is just a micro adjustment to compensate for cross winds so the pilot doesn’t have to constantly adjust the controls to maintain a constant heading.
This was an elevator tab.
Elevator trim is set for airspeed. Rudder trim, if it has rudder trim, can control yawl. There isn’t any aeleron (roll) trim.