Busted shifter knob

Get back from the morning "Drive The Geek to work, go back home for my own work" ritual and the shifter knob will only move between D and N. Hmm.... Trigger button is all the way in, why would...? Wait, trigger button is all the way in regardless of whether I'm holding it or not. That's not right...

So I pull the knob up and put it in the cup holder. Bare shifter stalk works properly pressing the release rod tip down with my thumb, so I'm saved from actual disaster in the form of a tow truck, and I'm booked in at Braeger Chevrolet for Thursday morning. But I'm really glad this didn't happen while I was in Park, with the sifter inside the little cubby and no room to lift it off.

Also, this is the first I've heard of this particular kind of failure...Even off, knob is still button pressed in, with a good spring holding it there, and it doesn't rattle so whatever broke inside jammed up good.