In an online conversation, gangstacow (19k) told me that the oddbot (12k) left in the middle of a game. My guess is that its system probably just rebooted as I have never heard of bots escaping. Of course, this could also be some new degree of versimilitude that's unique to its programming.
What I certainly did not know was that (some) bots resign games. After my at-home success against GnuGo 3.6, I decided to try an experiment against RankBot000 (13k) on KGS. I created a second account named CD02 and played against the bot with a 5-stone handicap to set the game at 18k. RankBot000 resigned after move 142 and gave my test account the provisional rank of 17k. If you're curious, you can see the SGF here.
I don't give much credence to ranks conferred by bots; as humans can be very creative. My success against GnuGo 3.6 does suggest, however, that it might not be difficult to progress beyond 22k when I get back to playing rated games.
My cold has stuck with me these past few days and seems to have gotten much worse. I hope it's not the flu.