They seem to have enjoyed it, but I couldn’t help shuddering at the thought of what would have happened if one of them had run into the propeller, instead of the entrance. Sliced base-jumper? Shredded chutist? Either way, it would have been messy . . .
There’s also the question of what might have happened if anything had gone wrong – a sudden wind swirl (not uncommon in the mountains), a problem with the aircraft (particularly a jumper hitting a vital control surface), or whatever. I think this was a very dangerous stunt from many perspectives.