The Twilight star had a recurring role as bad boy Kevin Volchok on the hit drama, playing a rival to MCKenzie's Ryan Atwood.
However, in a new interview with Elle magazine, Gigandet reveals their feud transferred off-screen, and when asked whether he keeps in touch with any of the actors from the show, he replied, "No. Actually Ben MCKenzie was kind of mean to me. I hadn't done anything at that point and he was a little bit of an a**."
He added, "But I love him. I think he's a great actor and I love (cancelled U.S. police drama) Southland."
Gigandet also took a swipe at Barton, who played Marissa Cooper, adding, "Mischa? I didn't really... Was she there? I don't even have memories of her."
Gigandet went on to note the rest of the main cast, including Adam Brody and Rachel Bilson, were equally hard to work with: "I learned a lot, but the things that I remember now - none of them are good... Those kids were f**king miserable.
"They were just - they would not remember their lines on purpose. They were young. That said, I don't talk to anyone I've ever worked with."
The O.C. ended its four-season run in 2007.