U.S. Supreme Court Justice Anthony Kennedy. Reuters/Kevin Lamarque A funny thing happened at the Supreme Court today in an important false-advertising case between Coca-Cola and the juice company POM Wonderful.

At stake is whether a company can sue a competitor for having a misleading label on one of its food products, even if the Food and Drug Administration hasn't said there was anything wrong with it.

Coca-Cola says there shouldn't be an issue with the label for its Minute Maid-brand Pomegranate Blueberry drink, arguing that it complied with FDA requirements by disclosing that the product is a "flavored blend of five juices."

POM Wonderful argues that since the drink is called "Pomegranate Blueberry," consumers would likely be surprised to learn that the drink is just 0.3% pomegranate juice and 0.2% blueberry juice.

Today, one of Coca-Cola's lawyers had an awkward back-and-forth with Supreme Court Justice Anthony Kennedy.

The controversial label in question. Minute Maid

Here's how it happened, according to the Supreme Court's official transcript of today's oral arguments.

Kathleen Sullivan, a lawyer representing Coca-Cola, was trying to tell the court that consumers aren't the sort of dum-dums who think that just because a juice is labeled "Pomegranate Blueberry" there will be lots of pomegranates and blueberries in it.

"[The FDA] said, 'You can use either flavor or a percentage, and it won't be misleading,'" Sullivan told the court.

"Why? Because we don't think that consumers are quite as unintelligent as POM must think they are," Sullivan said. "They know when something is a flavored blend of five juices ... the non-predominant juices are just a flavor."

It was then that Justice Anthony Kennedy piped up to say: "Don't make me feel bad, because I thought this was pomegranate juice."

Sadly, the Supreme Court does not allow cameras to capture comedic moments like this, but the official transcript indicates that Kennedy's remark was met with "(Laughter.)"

Sullivan, a super-lawyer with several high-profile Supreme Court victories under her belt, tried to power through:

But she was immediately interrupted by Justice Antonin Scalia, who couldn't resist the opportunity to make a playful joke at Kennedy's expense:

Paul Llewellyn, a false-advertising expert and partner at the law firm Kaye Scholer, said the funny exchange could be indicative of a serious problem for Coca-Cola down the road.

"The impression I had is that the justices generally had much harder questions for Coke than they did for POM," Llewellyn said. "They’re struggling with how something can be provably misleading to consumers without there being a false-advertising claim for a competitor."

The Supreme Court will issue an opinion on the case later this term.