"Common sense" is what people appeal to when they don't have actual evidence for their claims.
But we have the evidence. He was in bed when Oswald was supposed to be moved. The only reason he got up and went down was because a stripper rang to wire money. We have evidence he chatted to his neighbor. Not rushing. We have evidence of what time he was in the Western Union. We have phone records showing no calls were made advising him on Oswalds release and he made no calls regarding it. The Western Union had no TV or radio on with this info either. Ruby had no walkie talkie with him. There was no one in the WU office giving him visual signals. He simply had no way of knowing when Oswald was going to be moved.
We have evidence that Pierce drove the decoy car driving up the ramp, which meant Roy Vaughn stepped away from the ramp to direct the car out. Of course its possible I suppose that, Vaughn, knowing Ruby may be armed and willing to shoot Oswald, allowed him access. Or maybe another cop. A sort of spur of the moment nod and the cop was happy to let Ruby down to kill him. But theres no evidence for it.
CTers are the people making the claims. That Ruby was a hitman meant to silence Oswald. Theres no evidence for it and fairly strong evidence to suggest otherwise.
I don't know. See how easy that is to admit?
So do you believe the plotters were happy to just cut Ruby loose after he silenced Oswald? In the absence of any evidence we can only speculate and it makes no sense that they would silence one mouth only to have them replaced with a bigger mouth.
Who said he did?
The Dallas Police. Most of the people who were in the immediate area. As you well know.