This is not a 20 foot or less shooting scene with known parameters. It appears their model cannot handle the distance and unknowns. All they do is provide a graphic representation. The same can be accomplished with a paper and pencil.
The way to prove the SBT is to park the
jfklimo at Z218, with a Connally sitting (with a
bullseye on his back) & a jfk sitting (with
bullseye on his back/neck), & look throo
telescopic sights from up at the SN.
Then, by trial & error, arrange jfk & Connally & scope such that when jfk is removed the crosshairs on the scope are pointing at the bullseye on Connally.
If the position of Connally & jfk are nearnuff as per the Z frames before going behind the sign (&/or after emerging), then we have proved the SBT.
I think that there have been a number of tests over the years kind of similar to the above, & on each occasion the testers were happy with the SBT.
But i daresay that thems tests have had many
shortcomings (eg using Queen Mary).
Proper tests were needed.