I've always been under the impression that once airborne, you are in the country (and hence jurisdiction) of the country of registry of the a/c. So in this case, assuming Pace is flying a G-reg, the UK, no matter which airspace you're in. This situation would obviously change once on the ground.
Flying Lawyer ?
Will be very interesting to hear a qualified legal viewpoint on this ! The "G-reg = UK jurisdiction" approach would obviously make a lot of sense.
But I definitely remember being warned about deaths in foreign airspace on a couple of occasions while I was doing air ambulance work. It was a long time ago; maybe the laws have changed since then !
PS - I never did actually lose anyone in flight at all !