In his latest interview with Fox News, Donald Trump blasted Robert Mueller by saying the special counsel made a “fool” of himself with his recent press conference.

Trump was late for a D-Day commemorative ceremony on Thursday when his interview with Laura Ingraham apparently ran long, and the first details of their conversation include the president ripping Mueller’s public remarks about his investigative findings.

“Let me tell you, he made such a fool out of himself,” Trump said, “because what people don’t report is the letter he had to do to straighten out his testimony because his testimony was wrong.”

It’s not clear what testimony Trump was talking about, but he seemed to be referring to Mueller’s letter to William Barr, the letter in which Mueller criticized the attorney general for not conveying the full gravity of the special counsel’s conclusions.

While Barr has been favorable to Trump by dismissing the idea that the president committed obstruction of justice, Mueller said that Justice Department policies prevented him from charging the president, and, “if we had confidence that the president clearly did not commit a crime, we would have said so.”

Twitter was disgusted by Trump’s slandering of Mueller, especially on D-Day.

I know we’re all supposed to be cynical and unshockable but Fox News and Trump insulting Americans including Mueller (who received a Bronze Star and Purple Heart) in a MILITARY CEMETERY to mark fucking D-DAY seems to cross a line we still might have somewhere?

— Jon Lovett (@jonlovett) June 6, 2019

Trump just attacked Robert Mueller and Speaker Pelosi while at the American cemetery in Normandy, on the anniversary of D-Day, white crosses in the background and all. What a pathetic traitor.

— Scott Dworkin (@funder) June 6, 2019

While participating in D-Day celebrations, on sacred ground, with graves of soldiers in the background, the coward with fictional bone-spurs deemed it appropriate to attack Mueller, a decorated war veteran who was awarded a Purple Heart. Trump is a disgraceful embarrassment. https://t.co/xtXUhGrtzu

— Ana Navarro-Cárdenas (@ananavarro) June 6, 2019

Trump insults Mueller, who has a Bronze Star and a Purple Heart Medal, in front of a U.S. military cemetery. https://t.co/pgtBrOeCYa

— Kyle Griffin (@kylegriffin1) June 6, 2019

This is disgraceful. Trump lies about Mueller (a letter to correct what testimony?) & demeans the speaker of the House, using Normandy & the blood of the greatest generation as a backdrop. No American President should behave this way without condemnation from both parties. https://t.co/jbOJadJLC2

— Joyce Alene (@JoyceWhiteVance) June 6, 2019

Against the backdrop of D-Day commemoration, Trump uses Fox News to trash Mueller—a decorated war veteran—as “a fool.” Reminder: Trump ducked military service himself and glossed over neo-Nazism in Charlottesville. He will go down as a stain on US history. pic.twitter.com/G4W7FaFTCU

— Mark Follman (@markfollman) June 6, 2019