It's not the first time it happened to me. I had already a few games in which the support just take smite, give the first kill to the enemies - by running into their tower, then just follow the jungler and smite his jungle camps.
Is that like a popular trolling method? They even say CLEARLY in the chat, that they will prevent the team from winning. IN THE CHAT and Riot doesn't ban them. I don't understand it. Why is that not bannable? I mean, they are clearly trolling and even saying in the chat, that they want the team to lose.
In my last game, for example, Nunu support took smite, gave first kill at the start and then steal all the camps or went afk. I looked up his match history and whenever he doesn't get his role, he starts trolling instead of dodging.
The most important thing, Riot doesn't ban them!