Pauley Perrette, Mark Harmon"NCIS" fans were concerned when Pauley Perrette tweeted about "multiple physical assaults" on the set as the reason for her leaving the series after 15 years, especially when the actress didn't provide any more details.

Now, The Wrap reports that she was referring to a 2016 incident on set where Mark Harmon's dog attacked a member of the crew, who required 15 stitches. Several sources told The Wrap that Perrette objected when the dog was allowed to return to the set afterward.

The tension between Harmon and Paulette became so great, they weren't even sharing scenes, as many fans had noted. "She did her scenes on one day and he did his work on other days..." one insider said. "It was simply scheduled that they did not work the same days." (CBS declined to comment.)

Harmon's attorney, Barry Axelrod, confirmed to The Wrap that he consulted with Harmon about the potential liability of the dog returning to the "NCIS" set after the bite. And that there was something called a "one free bite rule," where the owner cannot be held liable for a first offense.

Axelrod claimed that the dog did not return to the set, but an anonymous source says that Harmon did bring his dog back, although it was on leash. According to The Wrap, no one set felt free to confront Harmon, an executive producer, about his dog.

Perrette has long been involved in animal rescue and would share photos of "NCIS rescue dogs" on social media.

Her character, Abby, was also a dog lover, even going so far in one case as to break protocol to prove that a German Shepherd was not responsible for mauling a man to death.

And, after "NCIS," she continues to rescue dogs.