That the Taiwan gov't prosecuting the pilots is a criminal case.
That the pax relatives sueing the pilots is a civil case. Probably the relatives are not satisfied with the compensations.
If pax relatives are really sueing the pilots, then they are probably sueing them for their neglience as professionals. Also, the relatives have to sue for something as remedies, for example, $$ compensation. They cannot just sue the pilots if they are NOT UNsatisfied with the compensations.
I would say the captain might have contributory neglience. Which means the captain is only part of the causes contributing to the accident. So the captain should not fully reliable for it.
SQ, as an employer, should be reliable for the pilots' fault as well if there is any.