There's lots of good technical, legal and regulatory stuff here, and quite a lot of people obviously know more about this than me. However, to close off some rabbit holes, the HSE prosecution, from my reading, seems to rest on MB knowing about potential faults on the seat, and failing to pass that information on to the end user. I think that is where MB have let themselves down here. It's not about safety cases, conspiracy theories etc, it's a simple case of a manufacturer having experience of faults on a product related to safety, and then failing to fulfil their duty to inform the end user. Whether this be through negligence, incompetence or malpractice will be for the court to decide.