An Employers responsibility to an Employee on H&S grounds, which is what I think your quote from Lord N referred to (given the "safe system of work" section), is based on a principle of ALARP.
My reference to Lord N's ruling was to support the claim that members of the services are employees, and that the mandatory route of the FAI act should be followed.
Safe means more than ALARP, it means Tolerable and ALARP (you can not have Intolerable and ALARP). According to the MAA RA the Duty Holder is required to justify his Tolerable and ALARP statement in a court of law, in the event of an accident. Let's not forget that this so called "safe system" resulted in the death of three people and the loss of two aircraft.
DV