Rudder knob in cockpit mistaken for door latch

Any aviation experts want to chime in about a knob turning a plane upside down? Also, please note this was characterized as “pilot error.”

Pilot error causes airliner to flip, fly upside down

From the article:

According to the safety board, an analysis of the aircraft’s digital flight recorder indicated the co-pilot, alone in the cockpit while the captain used a restroom, mistakenly turned the rudder trim knob twice to the left for a total of 10 seconds.

The co-pilot apparently mistook the knob for the cockpit door-lock switch as he tried to let the captain back in. The mistake is believed to have caused the airplane to tilt leftward and descend rapidly.