Thiel, a PayPal founder and early Facebook investor, recently revealed that he was secretly backing Hulk Hogan's lawsuit against Gawker, resulting in a $140 million verdict against the website and threatening its existence. Facebook, meanwhile, has been working to appeal to news organizations so they will use its products like live video and Instant Articles.
"Peter did what he did on his own, not as a Facebook board member," Sandberg said Wednesday at Re/Code's Code conference in Rancho Palos Verdes, California. "We didn't know about it."
That contrasts with how Facebook dealt with another outspoken board member, investor Marc Andreessen, who angered Indian citizens when he suggested that they should be more open to Facebook's Free Basics product for new internet users. Andreessen alluded to how colonialism helped the country, and how the online initiative would, too.
That prompted Facebook Chief Executive Officer Mark Zuckerberg to weigh in, saying that Andreessen's comments "do not represent the way Facebook or I think at all."
In that case, "it almost felt like he was speaking for Facebook," Sandberg said of Andreessen. "We felt we had to comment."
"We have very independent board members with very independent thoughts that they share publicly," she added. "They are not afraid to think differently and I think that serves Facebook well."
Sandberg also rebuffed speculation about her taking on the role of CEO at Walt Disney Co., saying: "I don't want another job." That includes running for political office, too.
Chief Technology Officer Mike Schroepfer will also stay at Facebook, he said at the conference.
© 2016 Bloomberg L.P.