There are 2 ramps, one from Commerce street, the other from Main
street. The one Ruby came down was opposite from the ramp the armored car
was parked in. I thought that was common knowledge. The car Pierce was
driving went up the opposite ramp the armored car was parked in, Duh!
Ruby was being honest about why and how he shot at Oswald, I don't
think he would lie about what ramp he came down just to cover for the cops
in the basement. The explanation he used was that he came down the ramp
when Vaughn's back was turned. He could just as well used that same
explanation to cover for the cops in the basement IF he came in through
the basement door. Why make up a story about coming down the ramp,
something that could easily be disproven? There were many people in the
basement that could have seen him and would contradict his story for all
he knew. If he's caught lying about one thing then that would destroy his
explanations about everything, no credibility.
I think the people most likely to lie in this scenario are Vaughn and
the off duty cop across the street. Both would want to protect themselves
against negligence and the reputation of the Police Dept. It's easy to
say you didn't see something, you can't prove somebody DIDN'T see
something, you have to take their word for it, it's a 50-50 proposition.
It is also very possible they were telling the truth. Just because you
didn't see something doesn't mean it didn't happen. I was looking for the
solar eclipse that other day, I didn't see it, but it did happen, I was
just looking from the wrong place. Vaughn had his back turned so maybe he
really didn't see him. The cop across the street, who said he didn't see
anyone go down the ramp, could have been looking elsewhere at that time,
it did happen quite fast.