Let's face it. Zavada really has no idea whether he was looking at the "original" or some variation of the "original". Time/Life bought the original and from that point who knows what happened? Time/Life owned both the original and had Josiah Thompson on their payroll. They were playing both ends against the middle, and possibly acting as a firewall for the CIA. There were "Briefing Boards" prepared from the Z Film on both the Sat and Sunday night following the assassination. My thought is the CIA had prepared a Z Film alteration and submitted that for the Briefing Board sessions. The final hurdle was seeing if their Z Film/alteration could pass the scrutiny of CIA Image Expert Brugioni. Why else would they hold 2 "Briefing Board" sessions only 1 day apart for the same exact film?