Correct, the autopsy permit, not the death certificate... but where does it say what you claimed it says, that Tippit "was DOA at the hospital at 1:15"? I think you're wrong.
"Place of death: DOA Methodist Hospital"
"Date and time of death: 1:15 PM, November 22, 1963"
The actual death certificate says that he died at 1:15, but his injury occurred at 1:18. Go figure...