I know we had the rescue thing in spoilers somewhere.
Both sides of the detour appear to me to be pretty common alpine search and rescue techniques. Search in a crevasse for a dummy and rescue it. Or search in simulated avalanche field for a dummy and rescue it. Hard to tell where any team is going just from the walking part. Appears the helicopters take them all to the same approximate place on the glacier and then they can decide at the last moment or at least they can decide while still in the air.
The avalanche field seach/rescue, reminds me of TAR11 in Argentina. Just after Rob/Amber were eliminated, teams had to go up a ski lift and search a glacier/snowfield for a buried clue, using the same technique they are using in this episode. I think in TAR11, it was just the route marker to fly to Africa though becuase all teams had to do the same thing and both teammates did it together.
Looks to me that Gary has the yellow/lime green windbreaker over a navy blue coat and Mallory has the windbreaker over a red coat. I dont know how much the color scheme has to do with a particular task. All teams appear to me to be wearing a yellow harness and safety pack on their backs though.