PAN call - I have a problem which requires that I have priority handling in order to get on the ground as soon as possible.
Mayday call - I have a problem and need priority handling as above, also the outcome is uncertain. I may also need ambulance and hospital support.
In this case - full AC and DC is available, albeit from one source. Land at the nearest suitable - but do you really need to "skip the cue" or have special handling (like a long straight final, only left hand turns etc etc)? Would you want to go in front of a medical emergency?
I would be happy without a Pan call, certainly in daylight, provided I was happy that the failures weren't linked (i.e. I am satisfied that the remaining source only has the usual (small) chance of failure.)
I certainly wouldn't hassle anyone who did give a pan call.