Sorry, but your hypothesis of malfunction would include aural cockpit warnings...there were NONE.
There wouldn’t be any audible alarms. The flight computer thought it was doing the right thing, just like the one that overrode the pilots and flew into the ground in the Habersheim airshow, and the Air France flight that flew into the Atlantic after the pitot tube iced up and the other crashes that have been blamed on the Airbus flight computer. That’s the point. Read the previous accident conclusions provided by the NTSB/FAA for the A320.