Can people that afk often get permanently banned?

So earlier today, i played a game where we were winning pretty hard, until Alistar decided to afk in base, and then minutes later quit the game all together. We ended up losing because of this, and it pissed me off, to the point where i wrote an essay on the report screen after the game xd My question is, do people that do this get permanently banned like toxic players? Because, unlike toxic players, where you can mute them, you cant really reconnect someone to the game.