Not being of a military background I mayhap speak from ignorance, but somewhat noisy, weather conditions limitations, and delay in wielding a weapon due to time it takes to remove the attachments? However, I see a future for first response paramedics in difficult to access environments such as mountain rescue scenarios.
I've had to board ships at sea in all types of conditions, climbing up a rope ladder with all your kit on your back is dangerous even in a light swell with good conditions. This test proves that there is another option, rather than climbing up the side of a ship, or fast roping down from a helicopter ( which can be tracked on its approach and 'is' very noisy).
It's about getting him quickly to the site of an injured casualty to give immediate first aid... once a casualty is stabilised and being monitored, the rest of the team or a rescue helicopter can arrive, safe in the knowledge that there is someone with the casualty... and of course, he's not going to be able to carry the casualty out... use your loaf lad!