In reply to KCheung:
I'm on a MRT, so have some (limited) knowledge of this...
Police Scotland provide a level of insurance for all MR members when undergoing formal training or on a rescue. However, I've not heard of this issue being raised by Lochaber to Scottish Mountain Rescue, which is the representative body for all MRTs in Scotland. This is surprising given how strongly Lochaber seem to feel about it.
With regards to difference between Police Officers and MR volunteers; when a Police Officer is on a MR call out, he officially is on duty. Therefore he is insured as a Police Officer and an employee with benefits that will be linked to his employment Ts&Cs. Volunteers are given a standard level of cover that will understandably be different - for example, the insurance can't be linked to their pension entitlement as they're not employed by Police Scotland. It's just not sensible to compare the two.
However, if there is an issue with the insurance entitlement then this should absolutely be addressed. Personally, I know what cover is provided and I'm perfectly happy with it (as are my family).