Matt Damon is under heavy fire from liberal-leaning media outlets for a segment on his HBO reality show Project Greenlight in which the actor-producer offered a comment on diversity in the film business to a successful black female filmmaker.

Sunday night’s fourth season premiere marked the first episode of Project Greenlight in more than ten years. The reality show follows Damon, pal and collaborator Ben Affleck, and other producers as they attempt to put together a crew to make a film.

In the episode, Damon, Affleck and the producers are discussing possible directors for the comedy film they’ll be making this season, Not Another Pretty Woman. The film centers on a man who gets dumped on his wedding day and later marries a black prostitute named Harmony.

During a debate on which director to select from the shortlist, Damon got into a contentious exchange with the only black woman in the room, producer Effie Brown, who has worked on several films including last year’s Dear White People and In The Cut.

After Brown suggested that hiring a more diverse filmmaking team would ensure the character of Harmony, the only black character in the film, would not be bogged down in stereotypes, Damon offered his own opinion.

“When we talk about diversity, you do it in the casting of the movie, not the casting of the show,” Damon said, suggesting that having a diverse cast of actors playing the parts is more important than having a diverse filmmaking team behind the scenes.

“Wow,” a shocked Brown replied.

Left-leaning media quickly exploded. Jezebel called the comment a “whitesplaining sermon.” Mic wrote that the comment “was not just tone-deaf, it was aggressively ignorant.” Vox’s headline read: “Matt Damon inadvertently demonstrates why Hollywood isn’t more diverse.” Salon: “Matt Damon needs to open his eyes on diversity.”

#Damonsplaining began trending on Twitter Monday. Thousands of users took to the social media site to rake Damon over the coals for the comment.

https://twitter.com/aliciafiasco_/status/643633764783026177

True diversity can't just occur in front of a film camera. It must occur behind the camera and in Hollywood boardrooms. #Damonsplaining — Omar Moore (@popcornreel) September 15, 2015

"You see, successful black woman, diversity is whatever white, straight, men say it is." – Matt Damon, 2015. #Damonsplaining — Derek Halliday (@DTHalliday) September 14, 2015

If at any point u grow tired of #Damonsplaining tweets, think of how sick PoC are of being 'splained to, insulted & expected to stay quiet. — lauren warren (@iamlaurenp) September 14, 2015

Damon’s comment and the ensuing media firestorm come as diversity in the film industry has come under increased scrutiny. Several recent studies have shown that women and people of color are underrepresented both in front of and behind the camera.