Ya know, this is quite a good topic. I have to reiterate that sometimes planning just isn't enough...when the weather goes to cock or you're in an operational situation (like the SAR described by Umm) then all the planning in the world doesn't help...knowledge of your aircraft and the things you can do to improve your chances to get back DOES.
The situation described by Umm Lifting, where the bingo light goes off and THEN the missing man turns up is classic...not exactly the same, but I've had that very thing happen myself...you're right, there are a lot of things rolled up into one...at the end of the day, sometimes leaving that guy out there (maybe with a raft and a long burning smoke closeby) is the best option...going in the drink with your aircraft, crew and the first two survivours does nobody any good (I'm not criticising you mate...believe me!).
Anyway, hope we can carry on with further useful additions to this topic.
Gentlemen.