Agreed. This is a pretty unforgiving business..... it has to be. With lawyers who "specialize" in suing trucking companies watching on one side and an over ambitious government on the other, trucking companies are under more scrutiny than ever before. Let's face it, if your brother got in an accident..... having a DUI and a 5 year suspension on his record would be a lawyer's wet dream. Even if he were not "at fault", that could tie the carrier up in court battles for years and cost them a crapload of money. Heck, even if they (and your brother) won out in court in the end, the media has a field day dragging their name through the mud.... which costs them a bundle of money in lost customer base.
Is it fair? No, of course not. But it is the reality that each carrier has to face these days.
Now, having said that..... your brother apparently has a CDL now. Ok, long haul, OTR and the "main stream" is closed to him for awhile. Guess what? There are hundreds of other jobs out there that a CDL is required for that are not automatic targets for the " big rig" lawyers. No, they aren't what you immediately think of when you say "trucking". Shunting trailers at a warehouse for instance. Drive a wrecker, do deliveries for a lumber yard, etc, etc.
But you better get one fact through his head. He's going to have to leave booze and "recreational drugs" totally alone. Because the next time he FUBARs up he's completely done.