Frangible or exploding bullet
Rumor Contested Alternate mechanism
Online / Owens overlay: the wound looks too destructive for a conventional .30-06, so the round was frangible or explosive. ATF could not tool-mark the jacket fragment to the rifle. That is common with deformed fragments, not a second mechanism.
Inconclusive comparison is not ‘wrong gun’ and not ‘frangible proof.’ Recovered jacket plus a GSW-neck autopsy is still a bullet story. A frangible claim needs the lab on the fragment composition, not a YouTube wound freeze-frame.