Robin400,
Generator load will have little effect on main rotor rpm. When multi-engined helicopter generators drop off line, automatic load shedding is often designed in. But this is for reasons of generator loading, certainly not to maintain main rotor rpm during autorotation! With both engines shut down, the landing lights/search light would be powered by the aircraft battery, not a generator.
Autorotations are not flown on instruments in VMC, especially in the final stages. It's highly unlikely that radalt inconsistency was a factor here.
Please now give it a rest. As you can see, folks are beginning to lose patience.