It's my understanding that Stallworth plead guilty to DUI manslaughter, got sentenced to a jail term, a fine, and had his license revoked for life. He also paid a substantial sum to the family of the victim to settle any civil liability he might have had. Whether I feel his sentence was too light or not, I can't say. I'd have to compare it to what others in Florida have received under similar circumstances. I haven't seen many cases where someone was killed. Mostly first time offenders who had one too many and made the mistake of driving home.
In my experience, very few persons with DUI get off. Most end up pleading to some kind of DUI offense with the respective penalties based on their past record. In those cases, the lawyer has typically informed the court and the prosecutor of any mitigating circumstances to ensure their client received a fair sentence under the sentencing guidelines and, if they're a first time offender, had the opportunity to resolve things without the conviction ruining their life. Most courts have some kind of program for first-time offenders which allows them to go through an intervention program in lieu of jail time. I think most courts, prosecutors, and defense attorneys want to see these people get help and be a positive contributing member of society. However, there are many traps for the unwary in the legal system, which is why it's a good idea to have an attorney help you if you've been charged with a criminal offense that carries the potential of jail time. The few cases where I've seen someone get out of a DUI charge involved police officers failing to follow proper procedures according to their training, which resulted in a successful suppression of the evidence.