A skydiver exits the plane at 8,500 feet and has a premature opening shortly after exit around 7,000 feet.
The bag comes out of the container as he's on his back and the parachute deploys behind him while he's head down. His body rotates forward through the risers, which causes the risers to get twisted in a step-through malfunction.
He does a controllability test and lands his main parachute with the step-through on his twisted risers.
At the risk of sounding like a broken record... pin checks, pin checks, pin checks. Gear checks, gear checks, gear checks. Tight closing loop and BOC, tight closing loop and BOC, tight closing loop and BOC. Pay close attention to where and how you sit in the plane, and avoid rubbing your rig on the plane door as you exit.