"The Senator who Suspected a JFK Conspiracy
Yarborough's Suspicion of Lyndon Johnson
"...There is the well-publicized story of Agent Rufus Youngblood, who reportedly threw himself on top of Vice President Johnson after the shooting began in Dealey Plaza.... Johnson, in a statement to the Warren Commission, mentioned the incident:
I was startled by a sharp report or explosion, but I had no time to speculate as to its origin because Agent Youngblood turned in a flash, immediately after the first explosion, hitting me on the shoulder, and shouted to all of us in the back seat to get down. I was pushed down by Agent Youngblood. Almost in the same moment in which he hit or pushed me, he vaulted over the back seat and sat on me. I was bent over under the weight of Agent Youngblood's body, toward Mrs. Johnson and Senator Yarborough....
However, former Texas senator Ralph Yarborough, who was sitting beside Johnson that day, told this author:
'It just didn't happen.... It was a small car, Johnson was a big man, tall. His knees were up against his chin as it was. There was no room for that to happen.' Yarborough recalled that both Johnson and Youngblood ducked down as the shooting began and that Youngblood never left the front seat. Yarborough said Youngblood held a small walkie-talkie over the back of the car's seat and that he and Johnson both put their ears to the device. He added: 'They had it turned down real low. I couldn't hear what they were listening to.'"
http://jfktruth.org/LBJ/DuckedBeforeFirstShotAtJFK/index.htmLBJ can be seen in an unusually low position in his seat, relative to his height, as his car is heading TOWARDS TSBD as in seen in the Hughes film.
Perhaps the real reason for box placed on window ledge in obvious plain sight, is that it was a signal to LBJ in the motorcade, that the operation was about to commence. LBJ might have actually thought the shots would be starting on Houston st, after seeing box on the window ledge.