My question is did the pilot have and engine failure and then shut down the wrong engine? Apparently it has happened before on this same kind of aircraft https://en.wikipedia.org/wiki/TransAsia_Airways_Flight_235
It's certainly possible. I worked aircraft instrumentation in the Air Force and occasionally we'd have to remove the entire instrument panel to facilitate some other maintenance. One time when reinstalling the panel, one of our guys laid down upside down facing the rear and connected all of the engine instruments backwards - left engine readings connected to the indicators on the right side of the panel. There was talk of court-martial, but they realized the Crew Chief didn't notice when he ran up the engines following the repairs, not to mention it was only on the third flight following the screwup that the pilot reported the reversal, and I think he flew the flight anyway.