Actually, if you are rope into a it’s pretty dang’d difficult to fall to your death, for an experienced person and that depends on the belay used.
I use the most basic one and I’ve found myself upside down before. Stoopit !!!
But, I’m no where as experienced as two men and really?? What are the odds two highly experienced and athletic guys are going to lose total control on belay??? Unless they both crossed their line on the opposite side??
Even then, it won’t result in a free fall. Will give you a fk’d up rope burn but, you land recover proper looping and it’ll hurt. But you’ll laugh it off. a f
Also, I’m not sure if the initial report has since changed, but I heard that they were over water, but did not die from drowning and that the impact was the cause of death.
The method we used to use would result in freefall if you lost your grip, the SAS complained about our old fashioned method and one of them lost his career that day rappelling from helicopters with us, from injuries resulting from his mistake.
Frankly, I don't even know how the modern version work, but I have the impression that more equipment than a rope and a carabiner and gloves, are used.