As for Oswald walking east or west on Tenth, Jimmy Burt saw the eventual killer walking west on Tenth for almost a full block until encountered by the approaching patrol car.
William Scoggins was sitting in his cab eating his lunch. The cab was parked on Patton, facing north, right near the intersection with Tenth. If the killer was walking east for some distance, Scoggins should have seen him. Scoggins insisted the no one passed in front of his cab.
Scoggins is not proof that the man was not walking west to east, but it sure seems to me that Scoggins would have seen him. Same with Markham.
I agree. But if Oswald had lived, Markham would be able to back him up because she told the Commission that Oswald was walking east right in front of Scoggins cab:
From the book "With Malice"

Now admittedly it looks like she is changing her story. I dont know if she is or not, or if that is just the way it seems. It just looks that way. But if she is right, Oswald could have been walking east for some distance and the killer was walking west for some distance. Oswald could have claimed this was proof he was not the killer and that he fled from the killer and thats why people saw him running down Patton.