AFK teammates, yet i can't leave.

I've had a few ranked matches where a teammate is afk yet I'm still punished for leaving the game. This happened once yesterday. My teammate landed and didin't move the whole game, and it even showed them having the disconnect symbol, yet even after my other mate and I died fighting, we were not allowed to leave without a penalty. Obviously, I closed the game to do something better with my time, but this is ridiculous for a game that's existed for 5+ years.