What exactly was burning in the fire? If the element failed, I could
see it getting very hot, arcing, maybe some small flames around the
element itself. But beyond that, for there to be any substantial
fire, you need a fuel source.

It was all just metal.

As you can see from the pictures, the element is blistered just in one six
inch spot ( http://www.flickr.com/photos/donnaohl/2923845900/ and you can
see the GE oven heating element is broken in another spot not far away (
http://www.flickr.com/photos/donnaohl/2923845906/ )

How could the oven element be "arcing" if it was an open circuit?