She was arrested and charged, and took the option of accepting a formal caution, which requires that you don’t deny committing the offence. If she hadn’t taken that option, she’d still be facing charges (and gaol time).

The other guy who was arrested for speaking the words is still facing charges, so far as I know.

From the Guardian’s coverage, though, it seems likely his actions will be covered by the ‘reasonable excuse’ provisions of the law. It seems clear he said it in order to educate the crowd and make a political argument against the laws, and even to discourage the crowd from saying it:

“I’m not sure if everybody here [knows] the history of the different slogans that the government is trying to ban us from saying, so [in] the interests of education, I want to explain [it] to you,” he said at the protest.

He went on to deny that the phrase was terroristic or antisemitic, saying it was instead a call for freedom and dignity of the people between the Jordan River and Mediterranean Sea.

“So when we say, from the river to the sea, we are calling for the freedom of the people of Palestine,” he said.

He discouraged others from chanting the slogan.

Moments later, as protesters started to march, he was arrested.