Expectations for selected role vs game

I got a game as bot. Once we got into game my support Ahri announced she was playing 'Ultimate Bravery' and started with boots and 4 pots. They were in the same club as the mid ramus that picked into vel'koz (rammus also started boots and pots). At the end of the game I reported them for unsportsmanlike. In my mind, when they signed up for a role, it created an expectation of behaviors with the assumption that the player would attempt to meet those expectations (supports ward and don't take cs, for example). Was I in the right, or can they play 'just a game'? On the one hand, they're playing to have fun, and what's wrong with that? On the other, it's my game, my time, too. I'm not expecting a great support, just someone who tries to fill the role.