The problem, it now seems, is not that the mechanical lock stopped working (now that it is out, the key can turn it properly) but I think something to do with the way it met with the plastic, electronic portion of the lock. I think what happened is that I tried to turn the car on and the lock advanced through all the notches without turning the plastic switch at all, and once it was all the way forward I couldn't turn it backwords. This caused me to think that the lock itself was jammed, when in fact it was just stuck at the end of its travel.
The switch has been sloppy for a while now, and, now that I think about it, perhaps that day was hot enough to make the plastic switch strip, letting the metal break past it and fail to engage anything.
In the end, I think the steering wheel lock wouldn't even have engaged if I did turn the wheel, and I could've hot wired it as it was.