Well, the way I see it, you've got 3 options.
- Dodge, and contact Player Support to file a complaint. You're down 3 LP, and he will receive a punishment after Riot checks it out.
- Don't dodge, play it out, and report the player for Assisting Enemy Team on the post-game screen. You're likely to lose the match, but the reporting system will flag his account even if didn't explicitly afk or intentionally feed (and it will be even faster if he did).
- The most obvious one: don't dodge, and then the troll dodges. You're down 0 LP and get to requeue immediately, and he's not going to be in your game.
Why would the troll dodge? Because just like you, he does not want to waste 20 minutes playing a game that he's going to lose... and then get reported on top of it. Given the choice between playing it out and losing and getting reported OR just dodging at the last second, which makes more sense? Of course he'll dodge. He's just hoping that he can get someone else to dodge for him, which is the entire purpose of trolling during champion select. If he was out to make people miserable for his own pleasure, he would wait until AFTER champion select to troll, wouldn't he? Because that way there's no chance for them to dodge and get out of it.
The people that you meet who troll in champion select are not out to antagonize you. They are out to gain LP, just like you are. They're taking a stupid approach that will get them into trouble, but their aim is the same. They want to win games, and they threaten to troll when things go wrong in order to try for a free dodge. Just don't give in, and they will dodge anyway.
The attitude that "I'll just troll if I don't like what's happening" is a shitty one, and it happens when people view champion select as a part of the game where it's not too late to hit reset. For a couple seasons, there was no penalty for dodging besides a time-out, and there were a lot more failed starts back then. People were a lot quicker to give up on compromising and pick Heimer or Eve (the troll picks at the time) in hopes of forcing a dodge, which they very often got. Allowing people to vote to kick someone out—even if you worked hard to remove all the abuse cases—would encourage this attitude. It would encourage the idea that "If things don't work out great during picks, we'll just reset and get into another game." It would make people feel entitled to a game where champion select went perfectly.
And that entitlement can backfire pretty badly. People have different views—in general, and in League. Entering queue with anything less than a full team of 5 means accepting that you will have people on your team who won't necessarily match your view. What happens if there's a Kallista/Garen duo, like the example you gave? How will the rest of the team react when they realize "the three of us can't win a vote to kick them, so we're not going to get the perfect team that we're entitled to"?
