Really, I think they did the right thing taking away his 'privleges'. They are doing him a favour and your mother a favour by showing they're true colours and lack of compassion. One more step out, one more push, and that'll be it! Your family will be out of that farce of a religion forever.
When the elders treated me like shit, I hated it at first, now I can't thank them enough. I'm sure your brother will feel that way too eventually, as do some of us.
They lack compassion on every level, but it's a good thing. They are more pharisitical (is that a word?) than any of the pharisees in Jesus time.