What exactly does Riot have to do with that in all honesty? I've had afks in my games before, typically ending in a loss (save for rare occasions). I understand your concern though and I do empathize with you. However, that was also kind of the point of dynamic queue. It allows you to queue up with all your buddies, and that way you don't have to control for the unknown variables such as the afk you may encounter.
Also, sometimes computers crash or restart at the worse of moments. I know it may seem impossible for it to happen twice in a row, but there have been instances where my client simply wouldn't let me connect to the game for some odd reason, and the moment I did, my computer decides to do an update. (I'm more mindful of my computer and its schedules now, but sometimes it catches you by surprise in all honesty.)