Andrew , the way it appears to me, at approx Z 226 , JBC right shoulder is moving FORWARD and his torso is rotating counterclockwise.
That’s NOT JBC turning ClOCKWISE , which is the way he must turn to look over his right shoulder.
Imo, JBC is HIT at Z 226 approx. This causes the forward and counterclockwise turn of his body which continues up UNTIL about Z 250-260
It is at that point when JBCs left hand with hat starts to go up and then at THAT point is when he starts to try to turn In the CLOCKWISE turn (reverse rotation) which is him attempting to look over his right shoulder at JFK, and after which he falls into Mrs Connallys lap.
In Dans scenario , as I understand it, the
shot sequence is 1st shot Z 224, 2nd shot =head hit at Z 313, (4.8 secs later) and then a 3rd shot which MISSED at 1-2 secs AFTER 313.
That fits the 1….2..3 sequence.
If I’m mistaken about Dans sequence and
it’s a 2nd shot BETWEEN Z 226 and Z 313 then that 2nd shot would be approx Z285 so that is just 1 sec Before Z313 . That never the less would ALSO fit the 1….2..3 sequence
Andrew, your scenario however, does NOT (imo) account for JBCs right shoulder rotating counterclockwise beginning AT 226 and continuing in that same rotation until about Z 250.