Fly with the autopilot on 200 ft. radalt over a calm sea: looking for trouble.
we seemed to manage for very many years in RAF and RN doing it - the only problems encountered were usually when the rad hold was left engaged as you coasted in - that resulted in a large upward movement of the collective on the Mk3 and lots of shouting
The radalt might lock onto the seabed in very shallow waters in very calm conditions (on old installations) but that probably accounts for a minute percentage of the user spectrum.
I believe it was the RAF Tristar fleet that had autoland fitted but not enabled due to issues with the manufacturer but some crews pressed the buttons anyway since the box was there and then complained about the accuracy of the system.
APs are great but you have to use them properly.