If you turn the governor off, the correlator will still increase the rpm if you raise the lever that much. In fact, I think it will do it more, since the correlator over-compensates if the lever is below 18 inches of manifold pressure.
It sounds to me like you raised the lever far too much. I teach my students that you really just have to hold the lever position, unless you started in a very high hover. More important, you need right pedal and right cyclic to prevent yaw and drift and land vertically. If you do that and hold the lever position, the helicopter should settle on to the ground with no problem.
I don't turn the governor off, and I'm not strong enough to get the throttle into the detente on some stiff R22s, but I've not had a problem teaching hover autos.