Crow
Crow Person
Well, the question swings on whether a ball was validly lost, or a concession made.
I think we agree that the ball was not lost (< mins, can't declare etc), so it is all about concession. Since the d was ambiguous at best and the player had asked the others, including his partner, to play on, I think it is reasonable to assume he was not conceding on behalf of him and his opponent, and in 4BBB the side wins or loses, concedes or not, as one. One player can pick up at any point but that is not the same as a concession; your side is still in the hole.
I am not sure there is a rule as such, but the other rules kinda point you in that direction. May be a decision somewhere.
I generally agree with that but I've never heard that a player is not able to "effectively" pick up if his ball has gone missing.
I can't see any reason why a player in a pair can't concede his own ball, but not the hole, after all one player in a pair can be DQ'd from a hole and his partner continue.
I don't have any leaning one way or the other, I'd just like to see the rule or decision that clarifies it.