No.
I'm halfway through "At the Cold Shoulder of History" part of which details James C. Jenkins' belief that the published autopsy photographs were not taken at Bethesda. Here's a fellow who was at the Bethesda autopsy and who has a photographic memory. Says he didn't give the JFK autopsy hardy any thought until receiving an interview request from the HSCA in 1977.
Now he's convinced there was an unattached brain sitting in the cranium when the body was brought in. I guess if he didn't witness firsthand Humes severing the brain stem. it must not have happened.