If it was planted there to incriminate Oswald that would prove that the conspirators had already designated him as the patsy. That wouldn't fit the argument here about that being decided after the assassination.
That wasn't my argument, Mr Hawthorn. I'm arguing that Mr Oswald was not set up
as sixth-floor gunman by those who planned the assassination. He may well have been set up as an accomplice. Heck, he may well have been an accomplice. We just don't know.
What I am very confident of is that he was telling the truth when he claimed to have gone outside to watch the P. Parade. It's the reason his claim was buried by the 'investigating' authorities!