The actress was the only star who shared a scene with Steven Wilder Striegel, and she demanded that he be cut from the film after learning he was a registered sex offender.
Movie bosses at 20th Century Fox agreed to erase the scene and director Shane Black has since apologised for hiring the man in the first place, revealing he lied about the severity of his past sex crime.
Striegel served time behind bars for trying to coax a 14-year-old girl into a sexual relationship over the Internet back in 2010.
But the drama didn't stop there - Munn, who is a fierce supporter of the #MeToo rights movement, has also attacked her castmates, stating she feels like she's the only one speaking out about the controversy.
Sterling K. Brown, who co-stars in "The Predator" has assured her that's not the case - and he's on her side. And now Holbrook has offered her his full support.
"I want to start by apologizing for this statement coming late in the current conversation," a statement from the star reads. "I do not take any of what has gone on lightly, and I want to speak from the most honest and genuine place possible.
"I have stated before, and I will state it again, I am proud of Olivia for the way that she handled a difficult and alarming situation, and I am grateful that Fox took the information seriously and took action swiftly."
Holbrook pulled out of "a small amount of press" over the weekend at the Toronto International Film Festival, because he felt uncomfortable having to answer questions about the drama.
His statement continues: "This type of social commentary is new to me and, given the nature of the originating crime, I felt further discussion could cause unwanted trauma and pain, neither of which I wanted to incite to the anonymous young woman (the 2010 victim)," he adds. "I now realize that my understanding of the situation was not the full picture and the last thing I want is for Olivia to ever feel abandoned or alone.
"We are in the midst of a very crucial and important time and it is imperative that we keep listening."