The singer and her co-defendants argue that the holiday mega-hit shares only "fragmentary and commonplace building blocks of expression" with an earlier song.
The rapper was arrested following an incident with a security guard.
"I regret they were included," the guitarist wrote of the "choice language" in the legal documents.
Though she won't force prosecutors to start from scratch, the newly installed judge reprimanded them for failing to turn over evidence to defense attorneys.
The case claims the earlier track was shared directly with the producer of Pitbull's song, who allegedly responded: "I love this song."
After cancelling all three shows this weekend following the disruption of the attack, officials in London say Swift's five shows there next week will go on.
The rapper was in the city to watch the U.S. men's basketball team play Serbia in the Olympic semi-final on Thursday (August 8).
The case claimed that one of the track's high-profile samples featured infringing lyrics, but those allegations likely faced long odds in court.
In this week's Legal Beat, a response to a billion-dollar copyright lawsuit, a court-ordered auction for Damon Dash, Cardi B files for divorce, and much more.
"This has been absolutely the most crazy insane scam I have ever heard of," the country star wrote on Instagram.
