Stepping back from the accountability argument, both occurrences need investigating. Pilots don't intentionally set out to crash aeroplanes, just as much as firefighters don't aim to kill the people they are meant to rescue.
If there have been failures (system, equipment or human), then once these have been identified they can be addressed such to minimise the risk to future passengers. Sure, if the final results of the investigation then hint at some form of negligence then let the lawyers have their moment.
Jumping on the 'hang em high' wagon isn't particularly helpful and does little to promote flight safety.