I always wondered who said it was a dummy reserve that Cooper got.
This FBI report says Cossey was the first to claim that, on 11/25/71
A reporter, Mr. Clossy, AP, Seattle talked to Cossey late afternoon or night of Nov. 25.1971 and got the story that one of the chutes was a "demo" chute.
Why was Cossey so knowledgeable, so early. Basically the next day.
file64 page 201