It may be that you are correct and that (b) is the
only way to go when it comes to allowing Police/HEMS winch training and ops, especially for training as a spare stripped out aircraft just for training? when training in this sectors is pretty much a non event as it is!
The exemptions governing using HEMS sites are many and if life saving of course operators are allowed to step outside the ANO and JAR. Wouldn't it seem reasonable then that you have to be allowed to train too and this is where I think the operators and/or getting the weight of public opinion behind this will cause exemptions/paramilitaries regulations to be written to allow winch training/ops to happen. Tightly controlled and limited but never the less winching.
One unit against EASA, well I suppose it depends on the size of the unit and who they have bating for them.
I'm sure this will make things "hot" for some time, whether or not Police/HEMS winching will happen eventually, if theres a will... to cut through the red tape forest