Well, Iīm not a mountain flyer but I know, itīs a standard practise.
Advantages are
- Quick(er) than whinching
- less power required compared to winching
- no winch required, no cycles on the winch, no risk of breaking it, snaggig the cable, getting it hot, having a fuse pop and all the other stuff which make a winch u/s
risks
- toching snow (probably a rock underneath) with the blades with all, what will happen then....
Personally I think, with experience, and it looks, he has a lot, and he can actually see the blades, I wouldnīt question his decision, bearing in mind it was an actual rescue and patches were already visible, so weather was also an issue to consider.
Guess it takes much more time to do all this with a winch and would also take much more concentration to keep the bird stationary witch all the white stuff around.
My 2 C worth ;-)