Yeah, it's really rare. The directory was a modified phpbb2. I didn't add any scripts known for self explosion. The subdomain redirect I had set up two days ago to direct
http://forum. to the phpbb2 install had reset itself to the redirect I had set up three days ago... This strangeness leads me to believe cpanel is responsible. Regardless, I'll back up and directories before changing a redirect in the future just in case.
Edit: A thought, Is this a cause or effect: Would a subdomain redirect change if the target directory wasn't present anymore?
Edit: It's looking more like user error since cpanel file manager drag and drop doesn't ask for directory move confirmation and I have found my forum files in an odd location. If it doesn't reoccur with the same scripts than I would consider this closed and the redirect issue relegated to the 'who knows' bin.