Speaking as an ex Lifeboat Coxwain that has done many deck transfers with the RN Seaking's from Prestwick every situation is differant. In general if the winchman was required to stabalise the patient or get him sorted into their own stretcher the cab would bugger off to loiter till called back in by the winchman ( less fuel is used that way than pulling high torque in the hover!! ) If the patient had been prepared and ready for transfer prior to the arrival of the cab then it would be winch down and straight back up.
In general we would not use a high line as the Arun lifeboat had a good clear aft deck and no real hazards......with a yacht a total differant ball game with a rolling high mast, in that situation the high line in general would be used to avoid hanging the winchman in the rigging!!!