No way to make an excuse for doing this, so I won't even try. I momentarily shorted the positive battery post to the ABS unit that sits right behind the battery. Neither battery cable was disconnected. It was a very quick light contact. The keys were out of the ignition. Have I likely damaged anything? If so, what are the most likely parts damaged? The car started up as normal and seems to drive like before.

Moral of the story: If you're interrupted by your wife while working on a car, stop working, shut up, and listen. This approach will get you back to the job at hand most quickly with the least damage done.