“Signing his own death warrant” is a very old metaphor, much akin to:
“Slitting his own throat”
“Biting off his nose to spite his face”
“Stepping on his own dick”
etc. The English language is wonderfully colorful.
Thanks for the information. I must say, your number four leads me to wonder if that guy would be a porn star!
I've got to say that I've never heard that before, but you nailed my lifelong problem.