That's the very definition of corruption. It does not have to involve anything monetary.
Yeah, that was clumsy way to phrase it, on my part. I think it's a problem with the AG being a political appointee position. Again, look at what Gonzales did under Bush, I don't even know what Clinton's AG did in the 90's. It's long been a problem. But, how do we define corruption here? It certainly wouldn't meet a legal standard, not anymore under the Supreme Court's recent rulings.
And, the law is able to be interpreted, that's what our entire system is based upon, so when you have a Barr (not a career law enforcement official) you get this kind of interpretation. They didn't just drop the case, they made a motion, in court, in a brief, that the charges lacked merit due to a complicated issue involving "materiallity" of the "lies" told by Flynn. Barr's essentially just a lawyer, interpreting the law as he sees fit, to back mostly his ideological agenda. I really don't think he is against the rule of law, this is just his interpretation.