Not suggesting any theory, but how would Bush know to be in Dallas to have Oswald killed by Ruby before Kennedy was even assassinated? Bush was there the day of the assassination before Oswald was arrested.
Not knowing anything, but there is a video on Youtube where Bush Sr. has the giggles when reminiscing about JFK’s assassination, while speaking at a funeral.
It would have been a lot easier for a conspiracy to whisk Oswald to a “safe house” - where he could be killed in private, and dispose of him via cremation, the way the mob did Jimmy Hoffa.
Jack Ruby was both an unlikely and unreliable hit man, and a police station an unlikely venue. Not buying it.
Time machines.
And Bush had those fake alibis ready right after the murder.