Sounds like a Clint Eastwood movie...
Interesting you mention that. The first time I read
the account I was reminded of Eastwood’s ‘The Outlaw
Josie Wales’. As to the authenticity there are two
witnesses. One is victim, Sam M Davis & the other is
William B Cox, the son of John Cox who was murdered
along with friend and fellow prisoner, Clemiel Davis.
William was a teenager who had been captured along
with his dad, Clemiel Davis, and Sam Davis. The
bushwhackers released William & told him to go home,
Instead he followed the group while staying hidden
Later, he shared his account in a letter. It was
similar to the account of Sam Davis.