Ethical queue dodging

I recently came into a game where i found myself in a lobby full of trolls. One had banned my pre-pick, so I was slightly annoyed at the inconvenience. I asked politely why they had banned the champion I wanted to play One of them decided to mimic my typings, while another was calling me a "butt-hurt pussy". I am very capable of playing other junglers, so that was not a problem. But i really did not want to play with a team full of people that were behaving poorly before the game even started. So, when it came to my turn to select a champion, I didn't choose one, and was kicked out of the queue and received the leaverbuster penalty. I understand that queue dodging penalties are there to decentivise dodging, but in circumstances like this one, I believe there should be a way to leave a lobby without incurring a penalty.

My idea for this would be akin to the reroll system for ARAM. The difference being you can only have oen queue dodge as oppose to two rerolls. It should also be difficult to earn such dodges say one for every 20(50? 100?) games, and do not earn credit towards the next queue dodge until you use the one you have.

Feedback?