Wow, this was so close to being a really bad day for this tandem. As the Tandem Instructor was moving towards the door, his reserve parachute deployed in the plane! Fortunately, the videographer saw it, grabbed it, and another TI helped control the situation. The door was immediately closed, the reserve was passed forward, and the plane landed with no further incident.
The submission details noted that they believe the TI snagged his reserve on the door track while he was moving forward from the bench.
Snag hazards are common on every aircraft and all jumpers should be aware of them. Every skydiver, from an AFF student to the most experienced examiner, needs to make sure that they aware of their surroundings and that their containers do not rub up against something that could dislodge a pin, snag a cable, or pull a handle.
This could have been a very bad day. But instead, thanks to staff members who were heads-up and reacted quickly, it just resulted in a plane ride back to the ground. The videographer on that front float was paying attention to everything that was going on, saw the threat and reacted instantly. The second TI, an S&TA, quickly alerted everyone to the situation and directed them to get the TI back into the plane, close the door, and pass the reserve forward towards the nose of the plane.