After launching a two-way horny gorilla exit, this jump escalated quickly into a scary situation with a horseshoe malfunction. When this skydivers corks to his back, the deployment bag leaves the container and the lines attached to his left riser pass around his body, between his legs, and his right leg passes through the lines. The deployment bag trailing behind him extracts his pilot chute, initiating a deployment of his main. Yikes!
This jumper appears to have brushed the outside edge of the door with his container while exiting. That action could have resulted in his closing pin becoming dislodged. Or rubbing the rig against the door could have snapped a worn-out closing loop.
Jumpers should exit the plane by rotating their body in a manner that prevents their container from brushing against the sides of the door. The jumper should have exited with his container facing away from the sides of the door and then rotated back to face his partner. By facing the front of the plane on exit he likely brushed his container against the door.
We can’t tell if this was the case in this incident, but these types of incidents have sometimes been attributed to jumpers not replacing closing loops. A worn-out closing loop can snap with little to no provocation. This can be easily prevented by examining closing loops while packing and replacing them if they appear to have more than 10% wear.