Nice videos, but they don't prove anything. The 101's famously strong downwash can only really be appreciated in the third video and it's way behind the aircraft, suggesting the wind is strong enough for the downwash not to be a hazard on this occasion.
The behaviour of the weighted orange sack in the first video is not representative of how a lightweight dinghy, lilo or small craft such as a dive boat, pleasure cruiser or small sailing vessel are going to behave when exposed to strong downwash that is directly beneath the hoist. It's therefore a bit much to claim that the 101 is the world's most capable SAR aircraft (as has been done twice on this thread) when this Achilles' heel would have a notable impact on the operating procedures adopted by the crew in circumstances such as these, not to mention overland situations where casualties may be perched on small ledges or steep slopes. Big is not always beautiful.