I've been meaning to follow up to my front diff failure with some pictures. Finally got some and figured out what happened. The results are somewhat interesting.
First, some broken ring gear teeth:

- Ring Gear 1

- Ring Gear 2
The pinion was completely frozen. I couldn't turn it no matter what I did.

- Pinion Broken
Upon attempting to extricate the pinion from the housing, I realized it was being held against not only rotation, but also against axial movement really well. Normally, you can hammer the pinion out of its bearing with a light hammer and a few whacks. This one required the 20lb sledge.

- Pinion Bearing
It seems the cage melted inside the bearing, seized up the pins, and then forced the pinion to attempt to rotate inside the inner race of the bearing until that galled up. My guess is that is why there are two distinct portions of ring gear teeth missing.
I should have also gotten better pictures of the housing. It punched the oil-pan side carrier bearing into the recess in the pan, put a huge crack in the exterior housing, and sheared the rear diff mounting tab (near the pinion) off.
Moral of this story - don't forget oil.