Ray Santilli revealed that he only became convinced the producers behind the documentary genuinely believed in the tape's authenticity after hearing Jonathan Frakes' dramatic closing remarks. The decision to end the show with such an extravagant statement made him realize that the producers must have truly believed the tape was real. This realization was depicted in the film Alien Autopsy (2006).
Throughout the autopsy, you can see the hands of the clock in the background constantly changing, revealing it was a hoax.