#5 makes no sense. The sound of a high powered rifle at 90 yards is going to be plenty loud. It resulted in a jiggle 7-8 frames after the second shot and another 7-8 frames after the third shot. I see no reason why it would not have caused a jiggle on the first shot.
The problem is Zapruder never mentions hearing any sound for a first shot, anything to cause a jiggle. He said he heard two shots not three. Wouldn't he have heard the shot that caused the first jiggle?
So you believe he heard a shot that caused a jiggle even though he said he never heard one?
His WC testimony:
Mr. ZAPRUDER - Well, as the car came in line almost--I believe it was almost in line. I was standing up here and I was shooting through a telephoto lens, which is a zoom lens and as it reached about--I imagine it was around here--I heard the first shot and I saw the President lean over and grab himself like this (holding his left chest area).
Mr. LIEBELER - Grab himself on the front of his chest?
Mr. ZAPRUDER - Right---something like that. In other words, he was sitting like this and waving and then after the shot he just went like that.
Mr. LIEBELER - He was sitting upright in the car and you heard the shot and you saw the President slump over?
Mr. ZAPRUDER - Leaning--leaning toward the side of Jacqueline. For a moment I thought it was, you know, like you say, "Oh, he got me," when you hear a shot--you've heard these expressions and then I saw---I don't believe the President is going to make jokes like this, but before I had a chance to organize my mind, I heard a second shot and then I saw his head opened up and the blood and everything came out and I started--I can hardly talk about it [ the witness crying].
He said he heard the shot that caused JFK to "grab himself" (the first shot he heard) and then he heard the shot that killed JFK (the second shot he heard). Two shots. But nothing about any shots prior to that.