... ...
Because in civilian SAR, the rearcrew are not flightcrew (no licences) they are not allowed to be responsible for the navigation of the aircraft - this is such a waste of crew resources simply because civil aviation regards anyone not in the cockpit as cabin crew.
... ...
This is an area for which there has been some discussion in the UK and possibly elsewhere. Ideally, regulators will get a grip on this and the role of "SAR Technical Crew" can develop from 'trolley dolly in a dry suit' status to a licensed aviation trade encompassing what advanced SAR rear crew in various territories have learned across several decades of operation.
"If you think education is expensive, try ignorance."