I don't know how the queues work exactly but I'm not sure it restarts the queue. In my experience, sometimes it does restart and sometimes it doesn't. For example, when I queued up for Titan hard mode sometimes people would back out of the queue. When they backed out, sometimes all the members would stay queued up and other times everyone would restart in the queue because I would be the only person in the queue. So it could cost more than 30 seconds and I'm sorry if I cost someone 40 minutes or more.