http://www.mlit.go.jp/jtsb/eng-air_report/JA16AN.pdf
Above is the link to the Final report on an All Nippon B737-700 JA16AN nosedive from Upset at 41,000 ft on 6 September 2011. Nightime.
The 100-page document also highlights the 38-year-old co-pilot's delayed and confused response, which investigators attributed to gaps in training, undue reliance on automation and seeming anxiety about quickly letting the captain back into the cockpit. According to the report, "excessive dependence on autopilot" exacerbated "lack of full awareness about the need to monitor" flight controls. The co-pilot couldn't recall the stick shaker's activation, it said.
The report said the co-pilot failed to recognize there was a problem for 17 seconds, and then alternately pushed forward and pulled back on the controls. The captain, returning from a bathroom break, was locked out of the cockpit while the plane nose-dived and executed back-to-back rolls in opposite directions. The maneuvers lasted about 90 seconds, though passengers may not have fully realized what was happening because it was dark outside.
With the large number of the Boeing 737 Series operating in Australia, pilots should find time to read this lengthy report. The captain had left the cockpit for a toilet visit leaving the F/O alone up front. He had never been alone up front before, which considering what happened next is probably understandable. To put it bluntly he didn't have a clue. Yet he was certified as competent to be second in command. The starting point for the gyrations of the 737 through the F/O's attempts at recovery was he inadvertently actuated the rudder trim instead of the cockpit door unlocking switch. Angles of bank reached 130 degrees which is close to inverted. This was at night initially on autopilot until the autopilot gave up the ghost and said "All yours" Included in the report was comment that the operator did not include simulator training for high altitude unusual attitudes and stall recovery. Many operators don't either, considering it unnecessary.