PHILADELPHIA (AP) — After six years of legal wrangling and one Supreme Court review of Janet Jackson’s infamous Super Bowl “wardrobe malfunction,” CBS argued anew Tuesday that it should not be held responsible for the half-second of nudity.

The 3rd Circuit Court of Appeals in Philadelphia had thrown out the FCC’s $550,000 fine against CBS as arbitrary, only to have the US Supreme Court kick it back down for review. The Supreme Court pointed to its ruling in a Fox Television-led challenge, when it said the FCC could threaten fines over the use of a single curse word on live TV.

The FCC argued Tuesday that CBS was duly warned that its 2004 halftime performers might add some shock value to the act. Jackson’s choreographer had promised as much, FCC lawyer Jacob Lewis said. During the act, singer Justin Timberlake ripped off Jackson’s bustier, exposing her breast for nine-sixteenths of a second.

“There were considerable alarm bells about deviating from the script,” Lewis told the 3rd Circuit panel. “CBS had a duty to investigate.”

CBS complained that the FCC had previously applied the same decency standards to words and images — and excused fleeting instances of both.

Judge Marjorie Rendell seemed to agree, noting that the FCC could have stated in its rules that nudity was another thing entirely from bad language.

“(The FCC) had the opportunity to say nudity is different. They didn’t,” she said. “I’m trying to figure out how CBS or anyone else can be put on notice … when the FCC does not draw any distinction at all between the two fleeting things.”

Lewis replied that the duration of the offence is not the only factor, but must be weighed along with the content of the material, in this case Jackson’s bare breast.

“They have no argument that the image was not indecent,” he said. “While fleeting, it was patently offensive.”

The three-judge panel is the same one that heard CBS’ original appeal of the FCC fine, siding with the network in 2008. The judges noted the Supreme Court’s directive to review their handiwork. Yet they peppered CBS for other angles that might support their decision.

Corn-Revere complained that the FCC, through ad hoc decisions, was effectively changing its decency standards without telling anyone. What’s more, he said, the agency applies them capriciously.

“So if the 3rd Circuit got it wrong in our first opinion, how could CBS be expected to get it right?” Chief Judge Anthony Scirica asked.

The Fox Network case involves brief profanities uttered by entertainers Bono, Nicole Richie and Cher, sometimes on award shows.

The 3rd Circuit judges could remand the CBS case to the FCC for more fact finding. They did not indicate when they would rule.