https://www.quora.com/Can-fly-by-wire-planes-be-flown-manually-in-the-event-of-a-system-failure
https://en.wikipedia.org/wiki/United_Airlines_Flight_232
If it is computer can probably hacked given determination.
But as link above shows does not need to be hack- cascade event can take down an aircraft.
Notably in section on influence on Industry, this situation is programmed into fly by wire- irony is that if plane experienced same situation no guarantee that computer would be available.
I thought so. Thanks