I'd have to revisit the story to see just how that happened, but explosive decompression is a hell of a drug. When it's happened in the passenger portion of aircraft, seats have been ripped off the floor to which they're bolted. Pulling someone out of a loosely-fastened seat belt (even, possibly, a multi-point harness) isn't beyond contemplation.
The few times someone has been pulled out of a plane due to decompression has been because they were stood right under the panel that failed( Ahola 243 ) or have been sat right on top of the cargo door that failed (aa96 and Turkish 981 ). I'd love to know how decompression unbolted a seat.
As to your req: TWA Flight 800 incident reports claim that the pilot and 70% of the passengers were pulled from the fuselage following structural failure of the aircraft (the front 1/3 of the plane detached from the remainder following a fuel tank explosion). Several rows of seats were also detached.
Situation would have been massive structural failure and exposure of the aircraft interior to the jetstream and fireball, which is more than an explosive decompression, but it is a referenced case.
Specific mentions begin at about 20 minutes into the following video based on NTSB reports:
There's some mention of passengers being hurled from the plane in the NTSB accident report that I can find, but I can't find full cites for the claims of the video:
There's the fact that most of the passengers suffered "severe" trauma (described as "internal decapitation" in the video), likely from sudden deceleration as the nose separated.
Acking your cite req. I don't have one handy, though a review of decomp cases should be reasonable feasible -- there are pretty comprehensive lists of aircraft accidents. And I'll admit not being positive of my information, though I do believe there are cases where a seat or seats have been ripped out.
Read the book that includes this incident Emergency: Crisis on the Flight Deck. Pilot's have 4 or 5 point harnesses, but don't wear outside of takeoff and landing. In level, uneventful flight, it's just the lap belt. Further, if you're walking around, say to the bathroom, you might not yet be belted in.
