Ok, so they didn't measure themselves. Who did the measuring and what method and tools did they use to come up with the 45/60 degree figure?
Unfortunately, Tim, like you, I wasn't present at the autopsy, so I can't answer your question. However Sibert and O'Neill were and they reported what they heard. Or, because what they said doesn't agree with your bible, the Warren Report, maybe you think the FBI agents were just mistaken or lying,