Truth is that the official story changed as evidence come up that caused the previous story to be no longer sustainable.
3 casing can only be likely proof of more than 2 shots from 6th floor of TSBD.
As the sequence "eject shell, fire shot, eject shell, fire shot, eject shell and no shot" is as plausible as "shot, eject shell, shot, eject shell, shot, eject shell"
So now you are left with injuries... Initially Connally with multiple wounds from most likely 1 bullet and Kennedy with 2 wounds from clearly 2 different, with the both Connally's insistence on Kennedy injury from 1st shot followed by Connally's injury from 2nd second shot. So as we know the initial official story was Kennedy neck shot than Connally shot than Kennedy head shot.
Tague's testimony of a ricochet injury, from what he indicated was the 2nd shot, meant that there were either 4 shots (Kennedy, Tague, Connally, Kennedy or Kennedy, Connally, Tague, Kennedy ) or as is now the official story the first bullet that hit both Connally and then Kennedy. (Kennedy/Connally. Miss hitting Tague, Kennedy.)