Gary didn't say evidence is false. He pointed out that different people look at the Z film and interpret what they see differently. Of course you think your interpretation is the most rational. Everybody does.
I agree with your comment if you mean that one cannot determine when the shots other than the head shot occurred just by looking at the zfilm. An opinion as to when the first two shots occurred based only on the zfilm that conflicts with the other evidence is bound to be wrong. That is why the SBT is wrong.
However, the zfilm can be useful in identifying when the shots occurred if one uses other evidence to bracket the shot times. Then you can use the zfilm to narrow down the frame range for the shots.
For example, it is not possible to tell from the zfilm when the first shot occurred. But there is a strong convergence on the first shot being after z191. A first shot earlier than that conflicts with a great deal of consistent evidence. A first shot after z191 conflicts with no evidence. (By "evidence" I do not include interpretations of what people think they see from the zfilm). A first shot after z202 conflicts with other evidence, particularly Phil Willis whose z202 photo, he said, was taken an instant after the first shot. Jack Ready said he turned around to look behind him immediately after the first shot. He removes his right hand from the handhold and begins turning around at z199.
Not surprisingly, a first shot between those brackets, around z195, conflicts with none of the evidence, including the view of the President from the SN on November 22, 1963. The President is quite visible when he emerges from under the oak tree leaves when he is between the lamppost and the Thornton Freeway sign. He was opposite the sign at z200. This means he was completely clear of the tree at z195, not z210 as the WC found.

So the first shot is bracketed by z191 and z199. That is not an interpretation of the zfilm. That is what the evidence says.