I'm not suggesting their evaluation of their situation might have been off.

I'm wondering if the overall regional situation as seen at SAR HQ might have looked different. Maybe there are other missions going on and resources are stretched. Maybe detailed weather data not available on the helicopter makes it clear "now or never".

It's not hare to imagine a SAR commander who has an aircraft passing over the area anyway to at least do a short search even if a rescue isn't immediately needed, with an eye towards knowing where to go the next day if a rescue *is* needed.