You can also see the nice Phillips head wood screw with it's nice sharp pointy end in the lower left of the octagon box that was used to secure the fixture. That little piece of hardware had pierced through the hot conductor at one time and shorted out the cable to the bonded conductor. I'm happy that at least the minimal ground connection to the box saved the day.
It probably saved alot of time after dropping and losing the original screw to just use one that happened to be handy in the ol' tool pouch.
