First and foremost, we should remember that Connally himself, the guy who actually experienced the wounding, insisted he was not hit before Z229-230. After viewing the Zapruder film a few times for the WC, Connally said he was not hit before Z230. Two years later, in 1966, he was given the opportunity by LIFE magazine to study high-quality color prints of the Zapruder film under high magnification, frame by frame, and to take as much time as he felt he needed. After doing so, Connally insisted he was certain he was not hit before Z229, and he selected Z234 as the moment of the bullet's impact.
And, oh, well, of course you claim that Connally was "off" when he insisted he was certain he was not hit before Z229, even after he studied a high-quality color print of the Zapruder film under high magnification frame by frame. Somehow he just "missed" the specious pre-Z229 "reactions" that you and other SBT defenders claim to see in the film, even though Connally was the one who actually experienced the shooting and knew himself better than anyone else.
Obviously, Connally didn't see any significance in the movement of his right arm in Z226, certainly not as an indication that he'd been hit yet. Z226 merely shows the continuation of a movement he began several frames earlier as he was turning back from looking at JFK. You must be blind to claim that his movement resembles the sudden and dramatic jolting forward of JFK's torso and the upward flinging of his hands and elbows from Z226-232. You must be kidding.
Gov. Connally had good reasons for selecting Z234 as the moment of impact. One of them was that starting in Z238 we see a very definite change in Connally: his right shoulder rapidly collapses, his cheeks puff, and a pained expression appears on his face. The right-shoulder collapse matches Connally's earliest descriptions of the bullet's impact: he said the impact felt like someone hit him powerfully in the back with their first.
Lone-gunman theorists have fallen all over themselves trying to explain this dramatic, obvious reaction event, with a few even making the specious claim that the shoulder collapse is an optical illusion. Why does the Z238-242 reaction pose such a problem for WC apologists? Because they are chained down by the single-bullet theory (SBT), which requires that Connally was hit absolutely no later than Z224.
A Z234 hit makes perfect sense with what we see in the Zapruder film. It makes total sense that a bullet that hit Connally in the back would only take four Zapruder frames--4/18ths of a second or 218.4 milliseconds--to drive his right shoulder downward. 218.4 milliseconds is in the range of the speed of an eye blink. Eye-blink speed ranges between 100 and 400 milliseconds.
Similarly, the forced expulsion of air from Connally's lungs would have been quite rapid and forceful, quickly causing his cheeks to puff, just as we see in the Zapruder film virtually simultaneously with his right-shoulder drop. The cheeks start to puff just a frame or two after the right shoulder starts to drop.
And, needless to say, the shattering of 4 inches of rib bone alone was extremely painful and would have quickly caused a pained expression to appear on Connally's face. Forensic science tells us that when people experience a sharp, sudden pain, it only takes 150-300 milliseconds to react with a pained facial expression.
Of course, these reactions make no sense in a Z224-hit scenario. It most certainly would not have taken Connally's right shoulder 14 frames to begin to be driven downward, nor would it have taken 14 frames for Connally to react with a pained facial expression and for his cheeks to puff.
It is worth noting that Dr. Robert Shaw, Connally's chest surgeon, studied the Zapruder film and
concluded the bullet struck the Governor at Z236, "give or take 1 or 2 frames, and that Dr. Charles Gregory, Connally's wrist surgeon, opined that the hit occurred between Z234 and Z238.