I did find that install.php was still on the server. When I went to look for it I expected it to be in an Install directory so I reported that it was deleted. Then later I found intall.php in the main directory to my surprise. I have to assume, that someone ran that file. Because, as Michael said, it looked exactly like a basic install run off of an unconfigured install.php.
So, I ended up thinking it was all due to my inattention to removing that file.