I doubt that is the case. Leagues tend to have very strict restrictions/definitions for this thing. I don't think any CBA would grant a commissioner that much unilateral authority aside from the MLB's "best interest in baseball" clause but that is typically saved for issues bigger than player conduct. Either way, there has been no accusation of DUI by the authorities. Moot point by now.
Well goodell never really defined conduct detrimental to the league or w/e that blanket violation was called. If dui's are ultimately separate from detrimental conduct then I guess he wouldn't get in trouble for another dui (which this isn't and the only reason we're talking about this is because of the fucking lockout). But if he gets himself into trouble non drug/alcohol related he could be looking at a suspension cus there's no defined guideline