Jean Newman can see the front of the car at Z200. Newman's description perfectly coincides with the limousine being at the Z220s and the shot being heard then. That's about where the car had "just passed" her.
If you're arguing two shots only (based on witnesses like Newman), then the "first shot" occurred in the Z220s.
I'm saying some witnesses seem to have lost track of the first shot, probably because it missed and was perceived as a "backfire" or "firecracker" (plus motorcycles were accelerating as they left the turn and the crowd along Elm began shouting).
Could be that in some cases, the authorities asked them about the shots that struck and the witness didn't volunteer the shot that missed. Texans are independent to the level of stupidity; case-in-point: privatizing energy utilities.
No one lost track of the shots and Jean Newman was very clear as to when the first shot occurred and what JFK's reaction was to the sound. All of the eyewitnesses but Mary Woodward state JFK reacted to the first shot. The early missed shot was a nice idea but completely fails when the eyewitness testimony and physical evidence is applied or compared.
The HSCA acoustical analysis could not understand why anyone would refer to the shots as backfires.
All observers rated the rifle shots as very very loud, and they were unable to understand how they could have been described as a firecracker or backfire. Only the pistol, which was subsonic, produced a moderate loudness. HSCA Sound Analysis:
We requested three motorcycles to be running during the test to provide some background noise that would approximate the original listening conditions in Dealey Plaza. Unfortunately, these newer motorcycles were not very noisy,
but the shots were so loud that any reasonable level of background noise would have been low in comparison with the shots themselves. Our listening conditions were, therefore, essentially representative of those at the time of the assassination, except for our being able to hear some very-low-level, long-delay echoes that originally might have been inaudible.
"The buildings around the Plaza caused strong reverberations
or echoes that followed the initial sound by from 0.5 to 1.5 sec.
While these reflections caused no confusion to our listeners
who were prepared and expected to hear them they may well
inflated the number of shots reported by the suprised witnesses
during the assassination" HSCA Earwitness Analysis Report, pgs 135-137
The HSCA like the WC believed the media influenced the number of shots reported by the witnesses. Three became the go to number because of Walter Cronkite reporting Merriman Smith's bulletin of three shots being fired. James Altgens reported two shots being fired but was never read by Cronkite.
"'While recognizing the substantial number
of people who reported shots originating from the knoll the committee
also believed the process of collecting witness testimony was such
that it would be unwise to place substantial reliance upon it. The
witnesses were interviewed over a substantial period of time some of
them several days even weeks after the assassination
By that time
numerous accounts of the number and direction of the shots had been
published. The committee believed that the witnesses memories and
testimony on the number, direction, and timing of the shots may have
been substantially influenced by the intervening publicity concern
ing the events of November 22 1963" HSCA Final Report- pg 87