As often happens, the cable had gone out, so I switched it back on, and found that it was recording on the wrong channel (whatever it was on when it went out). By the time I reset TiVo and the channel, I caught the very end of Stella's interview. Grrr.
It should get the rest of the show, in any case. I'll watch it at 7:30 so I can zap the commercials.