I think we are all agreeing to agree here..
There is no doubt that the staff, be they operators, trainers, engineers or managers, all feel responsible, jointly, for what happened, and none are blameless, but things like "laziness" can be factored out if absolute set procedures are followed and recorded as such. Log books written and signed for, then books being checked and signed for before action takes place. It happens in industry and commerce everywhere when safety is crucial within processes, I had to read risk assessments before going onto the "shop floor" at work on a routine basis.
The cock up on the Smiler should not have happened, and could not have happened, if proper procedures had been in place and followed. Because such things were not there to be followed, sh!t happened.
We don't know what happened within Merlin afterwards, they did not say if anyone was sacked or disciplined as far as I am aware of, but you can bet the staff were under disciplinary investigation after the event.
Again I don't know, but I bet some staff were formally disciplined, but that is a confidential employment matter, corporate, and within Merlin. The judge probably knew more about this, and that would have been part of the value of the fine, but not something us mere punters, are allowed to know.
Staff were "dealt with", we just don't know how.