Broken Steering cable nut

[iwillnc]

Have a pic?
Is there a gap where you suspect it was cut? If no gap then I probably wouldn't give it a second thought.
It can be a pain to get the pitman out, therefore I highly doubt someone would remove it to cut it. Most likely manufacturing defect.

I'm surprised that you never changed the pitman since you've had the truck tbh, not that it should fail in such a way...