This was meant to be a 2-way coach jump with an additional jumper flying around them, with the option of the third jumper coming in for a dock if he felt comfortable. Jumper #3 approached the coaching pair way too fast, then had a premature opening as he passed under the other jumper! In that split second, the other jumper managed to snag jumper #3's bridle and it appears that the deployment bag flipped through a line group on deployment, causing a malfunction that had to be chopped.
The jumpers noted that the rig which had the premature opening was a bit older and was “apparently was not in proper condition for freefly.” They didn’t specify the issue, but – given that the pilot chute appears to be properly stowed and there was no impact during the jump which could have shaken something loose – it seems fair to agree with their assessment that this incident occurred due to improper gear selection for this type of jump. The jumpers noted that, after this incident, the BOC was replaced.
If your gear isn’t up to the task for freeflying, then you’re just asking for a world of hurt. Before leaving the world of belly flying, check with your rigger to ensure that your gear can go into other orientations (e.g. freefly-friendly), which can help prevent an incident like this.
This was supposed to have been a coached jump but they invited a third jumper along to fly around them and have some fun. There is nothing necessarily wrong with that, but coaches and organizers should consider whether the added fun of inviting an extra jumper is going to distract a student from focusing on the task at hand. And, given that this jumper came in way too fast and could have easily hit the student, it suggests that maybe he wasn’t skilled enough to have been invited in the first place.
This touches upon the previous note, the third jumper looks to have closed the distance between himself and the coaching pair at a very high rate of speed and looks to have just barely avoided a collision with one of the other jumpers. Simply put, don’t do that. Regardless of your orientation, the concept of level-slot-dock still applies.