How is this physically possible?

[Flyer3299024 0]

https://rumble.com/vhc22r-scary-parachute-accident.html

[Squeak 17]

5 hours ago, Flyer3299024 said:

https://rumble.com/vhc22r-scary-parachute-accident.html

It's called a Mr Bill :) 

[wolfriverjoe 1,340]

They both hang on really tight. 
They haven't accelerated enough for opening shock to be terribly strong.

I've never seen a BASE Mr Bill before, but I'm not surprised. It went quite well.
That's not always the case. 

[dudeman17 270]

Not sure why they called that an 'accident'. Looks like it went according to plan.

My guess is Flyer### is one of the participants?