[BostonCard]

The Pitt coach used a really questionable challenge earlier in the 5th set, asking for a net violation on Stanford. It was unsuccessful so I don't believe he had a challenge available for Rubin's hit on match point at 11-14. I was ready to turn off the game when the back referee signaled that it had gone long. Point Pitt, match over, Pitt starts to celebrate. But wait!! The up referee signaled a touch. Point Stanford. Not challenged. Play on. 

Then I think it was at 13-14 that Pitt was called for a violation that I did not entirely understand. The announcers tried to explain in the moment that it was something not allowed by a back row player. Can anyone elaborate?

While it definitely would have made sense to challenge a touch on match point had Pitt had the challenge, it’s unusual for the refs to be fooled into calling a touch that wasn’t there (usually, you will see the opposite, where the coach will challenge a potentially touched ball that went un-called).  The reason is that the refs can usually hear the ball go off the block.  Also, both the R1 and R2 signaled a touch simultaneously, and the Pitt reaction was pretty muted because the blocker knew it.  Thus, I doubt the call would have been reversed, though the replays on TV made it impossible to tell.

BC

[BostonCard]

The Pitt coach used a really questionable challenge earlier in the 5th set, asking for a net violation on Stanford. It was unsuccessful so I don't believe he had a challenge available for Rubin's hit on match point at 11-14. I was ready to turn off the game when the back referee signaled that it had gone long. Point Pitt, match over, Pitt starts to celebrate. But wait!! The up referee signaled a touch. Point Stanford. Not challenged. Play on. 

Then I think it was at 13-14 that Pitt was called for a violation that I did not entirely understand. The announcers tried to explain in the moment that it was something not allowed by a back row player. Can anyone elaborate?

While it definitely would have made sense to challenge a touch on match point had Pitt had the challenge, it’s unusual for the refs to be fooled into calling a touch that wasn’t there (usually, you will see the opposite, where the coach will challenge a potentially touched ball that went un-called).  The reason is that the refs can usually hear the ball go off the block.  Also, both the R1 and R2 signaled a touch simultaneously, and the Pitt reaction was pretty muted because the blocker knew it.  Thus, I doubt the call would have been reversed, though the replays on TV made it impossible to tell.

BC