My point with captains challenges is that sometimes they win, or don't lose the challenge, due to some other factor than the original complaint.
The blunker goes looking for other infringements. In Pappys case, Riff challenged the tap saying it was tapped then passed for the kick, so as it wasn't a 20/40, Riff get the scrum feed. Once the blunker showed there was no initial tap taken and bthe kick was legal, challenge is lost, play on. The fact that another player was in front is superfluous as the blind touchies or the Ref shoulda picked that up. That they didn't is a separate issue. We dont want the blunker ruling on absolutely everything. Why have Refs??
Rant over.