If it’s a second offense, good bye.
As others have mentioned, it should be handled on a case-by-case basis.
People make mistakes. People in their early 20s make more. BYU can turn it into a growth experience for these types of situations.
Yes driving under the influence can ruin lives. It’s not to be tolerated. There should be serious consequences for making this mistake. But it doesn’t need to ruin the offending student’s life.
Incidentally my brother was hit by a drunk driver and nearly lost his leg. He didn’t walk again for nearly two years. The driver was a college freshman.