Kaiser wasn't captured on Hollywood-quality film when he found the clipboard nor have CTs managed to time-travel so they could personally witness it.
Other than that, we have his statements made under oath.
Of course Kaiser had any, and every, reason under the sun to lie about a fkn clipboard. And whatever happened to the CTer/JAQer/OAKer eternally-adolescent schoolyard cop-out 'how does that prove Oswald shot anybody?'
-------
NEWS
FLASH
-------
In a vote amongst inhabitants on the far shores of the lunatic fringe, aka CT Wonderland, Lee Harvey Oswald (the lone killer of John Fitzgerald Kennedy and DPD patrolman J.D. Tippit) came in at a lowly No. 500,000 as the person in the city of Dallas most likely to have done what he did.