According to the French investigation bureau for State aviation safety (BEA-E), a technical malfunction stopped the pilot from also being ejected, which would have left the $80million aircraft to crash into goodness knows what.
The pilot somehow managed to fly the jet - without its canopy or rear seat - and land it safely, knowing that his own ejector seat could detonate under him at any given second.
Per Aerotime, the Ministry of Armed Forces will occasionally allow a government official or journalist to take part in an "observation" flight, which involves strict protocol, including a medical visit to the Center for Medical Expertise of Flight Personnel, and ten days preparation time to ensure the passenger is both physically and mentally ready.
On this occasion, the unfortunate passenger was a retiring French defense manufacturer, who was given the going away gift by four of his friends, one of them a former Air Force pilot -- and thus normal protocol was skipped.
Instead, a doctor examined him just four hours before the flight, who gave him the go-ahead provided he was not subjected to "negative load factor", caused when a jet climbs so fast those on board feel like they are upside-down. According to the report, nobody told the pilot this.
The report claims the passenger was extremely reluctant and "never expressed a desire to carry out this type of flight", but was given close to no possibility to refuse.
Despite his nervousness and complete lack of experience, he was largely left to strap himself into the cockpit himself; as a result his helmet and oxygen mask were both unattached, his visor was up, his anti-g pants were not on correctly, and his seat straps were not tightened properly.
The pilot took off and climbed at 47° (a typical Boeing passenger jet takes off between 7°-15°) -- and chaos ensued.
"Discovering the feeling of the negative load factor, the insufficiently strapped and totally surprised passenger held onto the ejector handle and activated it unintentionally," the report stated.
Because they weren't properly attached, the passenger lost his helmet and oxygen mask as he was shot out of the plane at 2,500ft.
He landed in a field close to the German border, suffering minor back injuries, and presumably the fright of his life.
Luckily the flight hadn't taken place over water, as yet another technical flaw prevented the ejector seat's raft from inflating, which would have seen it come to rest on the ocean floor instead.
The report commended the pilot for managing to save himself, the plane and anything else it would have crashed into, as he avoided all inhabited areas, dumped his fuel and then landed safely, before removing himself from the cockpit with the still-undetonated pilot ejector seat ready to fire.
"He then remained calm to pilot his plane despite the multitude of failure messages that the on-board computer displays and an unusual aircraft centering following the loss of the rear seat and the canopy," the report stated.
A cordon was then set up around the plane for 24 hours, as the ejector seat was diffused.
In its examination of the craft, the BEA-E explained that when either person pulls their ejector lever, the back canopy is shattered by a line of explosives embedded into the glass, before the rear passenger is shot out, then the front canopy is similarly destroyed, and the pilot is finally ejected.
However on this occasion, the explosion ruptured the casing of the sequence selector meant to trigger the pilot's ejection seat, so he was left sitting on the undetonated explosive in a half-open cockpit while he landed the vacated jet.