I opine that the flight manual statement "Land immediately" should be ammended to also say "... and crash if you have to", if that's the reality of the situation. Let's call it what is is!
Land doesn't mean on land...
From the TSB:
In helicopter operations, "land immediately" is considered the highest priority emergency situation, and it is generally accepted as representing imminent danger to the crew and passengers. To illustrate, two definitions are provided from similar-sized military helicopters operated off the East and West coasts of Canada.
CH-124 Sea King:
Land immediately - an immediate landing/ditching is mandatory. The consequences of continued flight are more hazardous than those of landing at a site normally considered unsuitable.
CH-149 Cormorant:
Land Immediately - Imminent danger exists. An immediate landing/ditching shall be made in order to prevent loss of life.
In the S-92A RFM and Pilot Checklist utilized by Cougar Helicopters, "land as soon as possible" and "land immediately" are defined as follows:
Land As Soon As Possible - Land at the nearest site where a safe landing can be accomplished.
Land Immediately - Continued flight may not be possible. Ditching or landing in hazardous terrain is preferable to continuing flight.