Oswald took 10.2 seconds to fire all three shots.

[Charles Collins]

I was responding to your statement that I was wrong when I said "The first cannot be reconciled with Altgens photo at z255.".  The "first" refers to Myers' web page which has W001 3.66 seconds before the head shot which puts W015 at z256-257.  I didn't say his "second" could not be reconciled with Altgens.  I just said it required the Cabell car to go from not being visible in Altgens to having completed the turn onto Elm in .76 seconds.
It is a bit difficult to stop Tyler's animation at the right spot.  He uses the 255.1 frame in the cover to his manual. I wasn't sure what frame you were using. There is not much difference, I agree. Besides, there is also some uncertainty in exactly when Altgens took his #6 photo - it could be z254-z256 based on Jackie's hand on JFK's right sleeve and the car-right flag flutter. I would suggest that z254-z255 is probably more accurate.
Myers' work appears to be, from an animation point of view, well done.  But the problems arise because it is not possible to check his work, being based on a model that he keeps secret and will not share.  He presents it as highly accurate but doesn't show any error range.  This is not the way a scientific analysis should be presented.  I would be interested to know how his model compares to the Knott Laboratory model created by using actual measurement data obtained by a laser scan of Dealey Plaza.

He presents it as highly accurate but doesn't show any error range.

On page 28 of the pdf Myers qualifies his error range for this project:

In synchronizing the amateur films for this project, an error ratio of plus-or-minus (+/-) one
frame (approximately one tenth of a second) was deemed acceptable, and therefore considered
synchronous.

Also, he does qualify the following on page 30 of the PDF:

Each of the nine amateur films used in this analysis was prepared from original sources.103

103. With the exception of the F.M. “Mark” Bell, and John Martin, Jr., films, which used the best available sources.