Just watched the relevant bit of yesterday’s Tirreno-Adriatico and it looks like the cassette did fall off Cav’s replacement wheel. The mechanic just stuck it back and put the wheel on!
Possibly, I just assumed that someone forgot to tighten the lock ring. Not really up to date with this modern technology. Only just got a disc brake bike, and I haven’t removed either wheel yet.
Just watched the relevant bit of yesterday’s Tirreno-Adriatico and it looks like the cassette did fall off Cav’s replacement wheel. The mechanic just stuck it back and put the wheel on!