[bucky]

OP contained 2 questions: How should it be handled and whose call is it?

I agree with Arem. Secondary defender came to help. C had the primary defender and can't really watch two defenders simultaneously with great accuracy. IMO, it is L's call.

I, with great respect, disagree with Mark T. as there still can be a "secondary" defender. It may not fit certain definitions of associations but for purely descriptive purposes, it works. Also, I do not feel that the L had a "competitive matchup" as they were doing nothing to warrant L's attention.

Now, everyone has already described how it should have been handled. IMO, L should have been ball side. When the ball crossed half-court, he should have been in a close-down position. When the ball went to the wing, he should have then initiated a rotation. Again, just my opinion.