CBS is stepping up its challenge of the Federal Communications Commission’s decision to fine its stations $550,000 for Janet Jackson’s 2004 Super Bowl “wardrobe malfunction,” telling an appellate court the decision raises First Amendment and due process questions and is arbitrary and capricious.

In a filing late Monday with the 3rd Circuit Court of Appeals in Philadelphia, CBS said the $27,500 per station fine against 20 CBS-owned and -operated stations was unjustified. It said Ms. Jackson’s breast-baring for nine-sixteenths of a second during the halftime show of the highest rated program of the year was a “blink and you miss it” incident—an “unscripted and unauthorized stunt” that CBS was unaware would occur, had no part in preparing and immediately apologized for.

CBS said the incident was neither explicit nor graphic, despite the FCC’s conclusion that it was, because few viewers actually saw the bare breast during real time. It accused the FCC of pursuing the incident based on Internet clips and unsubstantiated rumors that CBS or MTV, which produced the halftime show, staged the breast-baring. CBS also said the FCC has rejected indecency findings for far more sexually charged programming.

“The FCC determined that it was irrelevant that CBS did not intend to broadcast any nudity. … Similarly, despite undisputed evidence that CBS took steps to avoid even accidental breaches of broadcast standards, the FCC determined that the network had deliberately sought to ‘push the envelope’ of indecency,” CBS said in its filing.

“When the FCC’s inquiry failed to turn up even a shred of evidence suggesting that anyone at CBS participated in the halftime stunt … the commission retroactively applied a policy that abandoned its long-established approach to fleeting, insolated or unintended expletives and images [and] also held that advance knowledge of the incident was not necessary for it to find that CBS acted ‘willfully.'”

CBS claimed that the FCC’s adoption of a “zero-tolerance approach” was a repudiation of court rulings and an arbitrary and capricious policy change done without notice to broadcasters and inconsistent with the principle that the First Amendment requires breathing space to survive.

In a statement, the FCC rejected CBS’s charges.

“CBS continues to ignore the voices of millions of Americans, Congress and the commission by arguing that Janet Jackson’s halftime performance was not indecent,” FCC spokesman Clyde Ensslin said in the statement. “CBS believes there should be no limits on what can be shown on television, even during family viewing events like the Super Bowl. We continue to believe they are wrong.”