Far out. And what was LBJ's signal to give the "go" ahead? How did he transmit this signal to the assassin in the few seconds between when he could see the red rings and the first shot was fired?
After LBJ gave the "thumbs up" the hit team leader simply lit a big firecracker ( some folks thought it was a motorcycle backfire, while other witnesses thought the noise of the first explosion was a railroad torpedo)
Everybody in Dealy Plaza heard the "open fire" signal and reported that the first explosion sounded different than the gun shots which followed.