I've heard from reliable sources that if you have Beast in your party when you arrive at the Seeker Sanctuary, he can talk to Leya and have the collars removed without rescuing Gareth.

But if your avatar IS Beast, that doesn't happen. That seems very backwards.

Is it because Beast had his collar removed after winning in the arena? Even if so, that seems to be a pretty lousy penalty for playing as Beast instead of taking him along.