Well I think there were about 5 seconds of caving clips.
The caving challenge will be in Porth Yr Ogof later this year and a couple of the clips were actually filmed Porth Yr Ogof last Sunday.
Here's the complete video from Sunday's trip.
The caving bit of the Mother Of All Challenges should be on The One Show this evening.
See https://twitter.com/BBCTheOneShow/status/974334773102567426 and https://twitter.com/sportrelief/status/974320412749316097 and https://twitter.com/sportrelief/status/974203206774468608
Did Matt Baker really say it was in Snowdonia at the start of the show? (clip at end):
https://www.bbc.co.uk/iplayer/episode/b09vjh2v/the-one-show-15032018
Although not as bad as "we did as much as 10km a day" - "it was further than 500 miles, at least 800km!" - "they've been doing it for 1000s of years" (Camino De Santiago for Sport Relief).