There but for the grace of god go many of us, who can truly say that they checked every possible thing available to be checked, every time they make an Engineering decision.
However, this is not a new instance. There was a case where the engineers who designed a walkway that collapsed killing about 20 people were charged with, and convicted of, manslaughter. This is not a dissimilar case.
I think it's inevitable than any Engineer or technician whose decision has led to a death can expect at the very least a very robust investigation. If somebody has failed to perform to the very highest standards, they can expect reprisals. It's the form and source of the investigation and reprisals that are key.
I'd argue that the legal system jumped, inevitably because the Engineering profession is so poor at policing itself. If this was a medical cock-up, the offender would be up before the BMA (or equivalent outside the UK) - in other words a jury of his peers. They have the power to regrade, or even disqalify somebody. In extremis, they'd of-course refer something to the public prosecuting authority (Harold Shipman is an extreme example of just this).
I think we'd all rather our own mistakes, if (god forbid) we make any that cause death or injury, are judged by our peers than a criminal court. One might conject that a jury of Engineers would have removed the chaps license, and required a strenuous plan of education and supervision. Painful and humiliating, and probably should be, but far more constructive than 8 months inside (and may I make a point, he'll probably still have his license when he comes out - is that wise? for anybody?).
G