Should he receive punishment?

I just played a game with some friends on league that I don't with often. In this game our fifth which was a random chose voli, nothing wrong so far. He ganks a couple times and I start snowballing hard while bot and top don't do so well so I roam a fair bit. Now its around 15 minutes in and we start grouping. We don't really notice at first because im still stomping enough to carry the teamfights but voli isnt with us. Then their vayne slowly picks up speed and we start noticing. So we ask him to group, he doesn't. We ask again, he doesn't. The only thing he has said thus far is "First time voli". This behavior continued where he would only go into side lanes and split while we tried to group eventually leading the enemy team to beat us. So I want to know incase my report for this doesn't give me a punishment notif. Should he be punished?