You also missed the most reliable piece of evidence of an earlier shot, when Zapruder who was continuously filming while all three shots rang out makes three unique vertical reactions!!!
Zapruder up till and including the headshot only makes three startled vertical jumps while filming, the head shot at Z313, the shot when the Limo emerges from behind the sign and the earlier shot just before Rosemary Willis slows and turns when she says she heard a shot and Connally's quick head turn as confirmed by his own words, testimony which you conveniently ignored. -smug emoji-
Btw it took time for the gun shot sounds to reach Zapruder hence the slight delay in his reactions.
JohnM
Jack your comments, in every thread that i have recently read, are top quality, i have allways been very impressed.
But i wanted to point out that Oswald's shot-1 was back at the signals at about pseudo Z105, whereas Zapruder's sequence started at Z133.
Shot-1 was frame T137 of Towner's footage. T242 being the last frame of that sequence (this is my numbering i think)(not the official numbering)(i made my own frames).
I forget what her frame rate was, probly about 16 fps, compared to Zapruder's 18.3 fps.
Towner would have reacted (jiggled) at about T242, but T242 was her final frame, & there was no Towner jiggle as far as i am aware.
Oswald's shot-2 was at say Z218, sound hit Zapruder at say Z223, startle reaction would have been at say Z227.
The next problem is that Oswald did not fire a shot-3.
Shot-3 4 5 6 & possibly a shot-7 were from Hickey's AR15.
In any case the last shot was the headshot.
So, Hickey shot from say Z300 to Z312.
So, the sound would have hit Zapruder at say Z301 to Z313 (i am too lazy to do exact calcs).
There are 2 kinds of camera jiggle, we have the blast jiggle, & later we have the operator startle reaction jiggle (u of course know all of this stuff).
Anyhow, any worthwhile analysis needs to consider the above info (especially shot timings), which is beyond theory, it is fact.