New York. A longtime producer for Tucker Carlson is out at Fox News after he was deemed responsible for the on-air headline that referred to President Joe Biden as a “wannabe dictator" because of the indictment of former President Donald Trump.

The producer, Alex McCaskill, confirmed his exit in an Instagram post. Fox News did not comment on Friday.

He had remained at Fox after Carlson, the network's most popular personality, was fired on April 24. The reason for Carlson's sudden ouster, less than a week after Fox agreed to pay Dominion Voting Systems $787 million to end a defamation case, has never been publicly explained.

It was during the last minutes of Carlson's former time slot on Tuesday when the message appeared under separate onscreen boxes that showed Biden and Trump talking. It read: “Wannabe dictator speaks at the White House after having his political rival arrested.”

Carlson, in a Twitter monologue posted Thursday, said “the women who run the network panicked” about the post and scolded the person responsible. Carlson didn't name the producer, but said he was “considered one of the most capable persons in the building.”

The producer offered to resign with two weeks' notice, but was told to clean out his desk and leave immediately, he said.

Fox, in a statement on Wednesday, said the chyron had been taken down and the issue “addressed,” without further explanation.

In an Instagram message posted on Twitter by Justin Baragona of The Daily Beast, McCaskill is pictured outside of Fox's Manhattan office holding a box.

“Today was my last day at Fox,” read the message under his picture. “It's been a wild 10 years and it was the best place I've ever worked because of the great people I met. But the time has come. I asked them to let me go, and they finally did. To all my friends there: I will miss you forever.”

A call and text message to a phone listed as McCaskill's was not immediately returned.

Plenty of Biden critics have suggested politics was behind Trump's indictment by special prosecutor Jack Smith on charges of hoarding classified documents and resisting government attempts to retrieve them. Biden has not commented on the case.

McCaskill was named this spring in a lawsuit filed by a former Fox producer, Abby Grossberg, who also worked on Carlson's staff. Her lawsuit said McCaskill “habitually belittled female employees” at Fox. He said that a room at Fox set aside for employees to pump breast milk was a “waste of space” and should be replaced with a room for men to tan their testicles, according to the lawsuit.

Fox has denied allegations in Grossberg's lawsuit.