Julia Roberts spent time getting to know the real Erin Brockovich before starring in the movie of the same name–but not until the movie was halfway through filming. When American Crime Story: The People vs O.J. Simpson director Ryan Murphy spoke with her about how the interaction benefitted her, Roberts suggested his actors follow suit.

“I referenced Julia Roberts, who’s a friend of mine, and I asked her about it,” Murphy told reporters at the FX Television Critics Association Winter Press Tour on Saturday in California. “It was specifically Erin Brockovich. And she told me when she was doing that role, that she obviously did to great success, that she made a promise to herself that she would not meet the real Erin until she had half the movie in the can, because by then she felt that she couldn’t be swayed by in-person meetings, and she had already made her own decisions about certain ways to play things.”

“That really stuck with me,” Murphy added. “So I told the cast that was sort of, I thought, a very good rule to have. And for the most part I believe we stayed to that.”

So did the cast of American Crime Story: The People vs O.J. Simpson heed Julia Roberts’ advice?

#Throwback to 1990 when Julia Roberts rocked a suit at the #GoldenGlobes: https://t.co/HovhVk5ytm pic.twitter.com/lZg3unDNf2

— ELLE Canada (@ElleCanada) January 11, 2016

Some did, and some didn’t.

David Schwimmer of Friends fame plays the late Robert Kardashian. He reached out to his ex-wife Kris Jenner to learn more about the man he was portraying.

“Kris was really, really generous with her time,” he said. “It was really great to learn how much a man of faith he was and how loyal and considerate he was. He was a very humble, very private person. Not at all seeking the limelight, that was inadvertent.”

Ryan Murphy said not everyone tied to the infamous murder case was willing to share the way Kris Jenner was with David Schwimmer.

What’s your take on the advice Julia Roberts shared? If you remember her in Erin Brockovich, you no doubt realize she hit the nail on its proverbial head.

American Crime Story: The People vs. O.J. Simpson premieres February 2 at 10 p.m. ET on FX. Do you suppose Julia Roberts will be tuning in?