That’s what I understood from a documentary, I think it was from Al Jeezira, a civilian was pointing that there was a double radar echo from the plane and it meant there were probably two planes on top of each other.

Sure the article mention a theory that Gaddafi was in a fighter jet, and the civilian plane was a collateral damage from a dogfight, but given the lack of information in the public space, both theories still have a lot of common points.