The next problem
These are the reactions to the apparent shot at frame 285.
Each of those reactions began in the range of 290-292, or within the same 1/6th of one second.
That's not surprising, since Oswald's rifle was tested by the HSCA and proven to generate a 130 decibel shock wave, emanating directly from the bullet, followed almost instantly by a muzzle blast that was almost as loud. Other rifles are 2-3 times louder than Oswald's.
Of course, if Oswald fired all the shots, we would expect the limo passengers to have been exposed to the loudest and most startling sound levels when the earliest shots were fired. So why do we see no reactions then that are even remotely similar to the ones following 285 and 313??
There were certainly reactions, but they were spread out over roughly 100 frames. Why don't we see anyone ducking? Why doesn't Greer spin around like he did following 285 and 313 - so fast that some alterationists thought his turns were humanly impossible?
Even more troubling, is the fact that "most" of the witnesses who commented on the spacing of the shots, said they only heard one, prior to the very end of the attack, when they heard the closely bunched pair that could only have been the shots at 285 and 313.
I have a very hard time with a one-early-shot theory, but even if there were only one, shouldn't it have startled the limo passengers at least as much as they were startled by the final two shots??
If you have read the article I linked, then you know that John Connally testified that he clearly heard the first shot, which was undoubtedly, the one at 150-160. But he only "felt" the second. Since the witnesses, including all of the surviving limo passengers also reported hearing no more than one early shot, I don't think it's unreasonable to consider that this one was fired from a suppressed rifle of some kind.
It certainly didn't come from a high powered rifle - Oswald's or anyone else's.