The witnesses all claim he jumped out at 20,000 feet. This is impossible for a number of reasons. Above 10,000 ft, aircraft cabins are pressurized. There would have hundreds of pounds of suction holding the door closed. All modern aircraft are designed so that the doors cannot be opened in flight. If he had been able to open the door, the explosive decompression would have sucked him right out of the aircraft. And there would likely not have been any witnesses from the aircraft, as they would have died from a combination of exposure and hypoxia.