Not really. What he did was dumb and there is no question about that. However, once he gets convicted because he failed 2 drug tests he will enter the system under a drug/substance abuse classification. When he is in jail he will be in the drug program and must complete a drug abuse program that will allow him to get out sooner. Michael Vick did the same thing. It's a loophole in the system.
I'm not sure it's a loophole. From what I can tell the crime is attributed, in large part, to a substance abuse problem that is documented prior to the arrest. Looks like they aim to rehabilitate the substance abuse problem and thereby improve the person's ability to make clear decisions. Who knows if it's effective. I can't imagine it's any worse than serving the time given.
Looked around a bit for info on and found this:
http://www.famm.org/Repository/Files/FINAL RDAP FAQs 9.9.pdf
I'm not sure it will apply to Brent. Would he get sent to a Federal Prison because it looks to be only a Federal program?
Also, manslaughter is listed as a disqualifier. Not sure if they would differentiate for intoxication manslaughter.
He also may not get accepted to it because he doesn't have a documented abuse problem prior to the crash.
If he doesn't get more than 24 months he also can't be accepted and even if he gets more than 24 months he must have at least 24 months remaining in order to qualify and apparently the application process is timely itself which would mean his sentence is longer than Vick's and he won't play another down for at least 3 seasons.
And even after all that if he some how gets accepted he's only going to get early release to a halfway house, I believe. His sentence will still be running and while he might be living at a halfway house or be lucky enough to get sentenced to home detention because of overcrowding, I can't imagine the NFL is going to allow him to resume so long as his sentence is still running.