Parallel topic.
If it's determined to be a pilot error, what are the consequences for the pilot?
Would he get jail term for mass negligent manslaughter, or are there some exemptions for jobs like that?
Only if there is enough evidence that he acted criminal. It does not look like that now.
As the situation looks to me now (I can be wrong): He was a bloody beginner on the aircraft and should have let somebody more experienced with the aircraft handle the difficult landing. He was NOT the captain of this flight and not the most senior pilot in the flight deck during landing. The second pilot had twice the total flight-hours and over 3400 hours experience with the 777.
The only really poor decision I can see is the late call for go-around, after at least 5 seconds of warning signs. That is bad, but not criminal. Remember that he needed a moment to read through the instruments to make sense of the situation, maybe he just thought twice as long as he should have done.
That would mean most likely just, that he and the more senior pilot are both responsible for the crash and might still maximal face disciplinary punishments, like reduced salary, if at all.
So far, it sounds like an accident to me, even if a human is ultimatively responsible for not aborting when it was really about time for it. The crew will have to handle their own errors there and learn from them. Nobody of them deserves even to be fired, but they deserve badly to get their own errors analysed, so they never repeat them again.
More important would be fixing all the correctable problems, that led to the crash. Letting an practically unexperienced pilot handle a difficult landing is bad, but not a big issue (remember the touch-and-go of a German plane during storm strength side winds? this difficult and luckily non-fatal accident was flown by a rookie pilot as well. No fines or punishments for the crew, since she did the best she can). The actions of SFO are more critical there. Why has the ILS been inoperative? Had the final approach been directed wrong?