Kids' sports can be such a headache and it really shouldn't be that way.
Especially for kids this young.
When my son began baseball very young, they didn't even keep score. Of course many of the parents did. There were some parents who griped about every single thing and it could get quite obnoxious. One little boy was SO little that with his batting helmet on he looked like the guy in the movie "Space Balls". Another kid decided after his first game he didn't want to play anymore so he just sat in the field and wouldn't move even if the ball came 3 inches away from him. He did that for the complete rest of the season. Some parents were able to go and just see the humor in all of it and cheer the kids on. Some parents took it so seriously you'd think there were major league scouts in the stands or something.
Please don't take this the wrong way, I'm sure your brother meant well, but why yell out something for the refs to call? And then argue for even one second?
It sounds like the truth was obviously stretched and it's a bit harsh to eject your brother for the rest of the season. But, I would just let it go. I really would. I wouldn't drag the argument out any further.
I also wouldn't assume that certain coaches or refs have their own agendas or are jealous because one team is winning or whatever.
Take it from me, some coaches are just idiots. My ex husband wanted to coach one year and his heart was in the right place, but boy....did I hear it. He got the kids names mixed up, made goofy calls, gave the girls on all the teams extra chances. But hey....the kids were little. They all had fun. There were no "official" rules other than all the kids getting a chance to play and learn the different positions. Keeping score had nothing to do with it at that age. 4 and 6 year olds just want to play and have fun and I think that parents should have the same attitude.
That's just my opinion.
It sounds like your brother didn't say what he was accused of saying and that really sucks. But, do you want to involve yourself in an argument your brother got involved in or do you just want to let the kids play and finish out the season?
There are bad calls made, even in professional sports, it happens. It might not be fair, but it's not worth fighting about or getting ejected over either.
I'm sorry this happened and it's already been blown out of proportion. I wouldn't make it bigger.
That's just my viewpoint.