I'll just chuck in a point for discussion, I've only skimmed across the first few pages so I may have missed some bits:
The ALARP (As Low As Reasonably Practical) principle has been the corner stone of safety engineering for decades. The basic outline has been described as the application of more and more mitigations until you reach a point where further mitigation was unjustified on the grounds that implementing the mitigation would not reduce the risk further.
In crude terms, you add more and more mitigations until you reach a point where the risk is acceptable.
ALARP has been replaced with SFAIRP (So Far As Is Reasonably Practicable) sometimes referred to as SFARP. With SFARP the intent is that you start with a list of everything you could do, then discount or remove those mitigations that are not reasonably practicable to implement.
In theory ALARP and SFARP should arrive at the same point, but there is very little significant case law currently available to draw a conclusion. However there are some opinions that you are less likely to be able to prove that you have met SFARP than ALARP, because in the event of being taken to court you (as the defendant) would have to prove that you have indeed considered everything "practicable" and either implemented it or justified why it was not SFARP.
It may be that in this case the HSE are considering that MB did not meet SFARP by not doing everything reasonably practicable, including consulting, communicating and cooperating wit their customers.