The only thing that Bill's "reconstruction" proves is that you can make any timeline "work" if you make a whole bunch of non-evidence-based assumptions that are specifically designed to make it work.
But "it's not absolutely impossible" does not equal "happened".
As a retired lawyer, I would point out the distinction between "non-evidence-based assumptions" (i.e., pure speculation) and "reasonable inferences" from the actual evidence. In regard to the Tippit shooting, there is a mountain of actual evidence from which inferences can be drawn. Reasonable inferences, IMO, point
decisively toward Oswald. This doesn't mean there are no discrepancies or loose ends - there almost always are, in every crminal case. IMO, however, there are no discrepancies or loose ends that point decisively away from Oswald, or from which reasonable inferences pointing decisively away from Oswald can be drawn.
I'm always kind of amused at the extent to which conspiracy theorists seem to feel compelled to play the role of defense counsel for Oswald. In my life as a lawyer, I used to always say that defense counsel (including some of my best friends) seem to live in some alternate universe where unreasonable inferences and raw speculation are vastly preferred to actual evidence and reasonable inferences.
Your statement
But "it's not absolutely impossible" does not equal "happened'" reflects the defense counsel mentality: "If my unreasonable inferences and raw speculation are not absolutely impossible, you must acquit my ciient." Uh, no. If the actual evidence and reasonable inferences point decisively to Oswald, we are free to reject the alternate universe of his innocence.