That provision of the law is INTENDED to benefit a plaintiff winning its case against the govt on a Civil Rights enforcement action. BTW, that's often a primary reason why public interest firms take on marginal, e.g., prisoner's rights suits, and the like -- there are often no $$ damages owed to the prisoner, but the law firm representing the prisoner gets a nice check when they prevail.
Here the non-governmental party was the defendant, not the plaintiff, and the request for legal fees doesn't fit the intent of the provision, although its plain language allows the request. I think there is a less-than-zero change of the teamsters getting those fees -- it would be against common sense and public policy to award legal fees unless the action was deemed frivolous.
Against common sense? Yes. But the statute says what it says. So don't be surprised if the judge awards fees.