Courage Under Fire

While serving in the Gulf War, Lieutenant Colonel Serling (Denzel Washington) accidentally destroys one of his own tanks during a confusing night-time battle, killing his friend Captain Boylar. The US Army covers up the details and transfers Serling to a desk job.
Later, Serling is assigned to determine if Captain Karen Emma Walden (Meg Ryan) should be the first woman to receive a (posthumous) Medal of Honor. She was the commander of a Medevac Huey that was sent to rescue the crew of a shot-down Black Hawk. When she encountered a T-54, her crew destroyed it by dropping a fuel bladder onto the tank and igniting it with a flare gun. However, her own helicopter was shot down soon after. The two crews were unable to join forces, and on the next day, when further rescue arrived, Walden was reported dead.
Serling notices inconsistencies between the testimonies of Walden's crew. Specialist Andrew Ilario, the medic (Matt Damon), praises Walden heavily. Staff Sergeant John Monfriez (Lou Diamond Phillips) claims that Walden was a coward and that Monfriez himself led the crew in combat, and that the fuel bladder technique was originated by him. Sergeant Altameyer, who is dying in a hospital, complains about a fire. Warrant Officer One Rady, the co-pilot, was injured early on and rendered unconscious. Meanwhile, the crew of the Black Hawk claims that they heard firing from an M16, which Ilario and Monfriez deny.
Under pressure from the White House and his commander, Brigadier General Hershberg (Michael Moriarty), to wrap things up quickly, Serling leaks the story to newspaper reporter Tony Gartner (Scott Glenn) to prevent another cover up. When Serling puts pressure on Monfriez during a car ride, Monfriez forces him to get out of the vehicle at gunpoint, then commits suicide by driving into an oncoming train.
Serling tracks down Ilario using details about Ilario's preferred vacation spot. Ilario tells the true story, revealing that Monfriez wanted to flee while leaving Rady behind. As a result, Monfriez held Walden at gun-point. When Walden shot an approaching enemy, Monfriez reacted by shooting Walden in the stomach, then voluntarily backing off. The next morning, Walden covered her men's retreat using an M16, with the expectation that the rescue team would come back for her. However, Monfriez lied to the rescuers, saying that Walden was dead, which led to A10s dropping napalm on the entire area, leading to Walden's death. Altameyer tried to tell the truth but he was too injured to speak. Ilario was too scared and remained silent.
Serling presents his final report to Hershberg. Walden's young daughter receives the Medal of Honor at a White House ceremony. Later, Serling tells the truth to the Boylars about the manner of their son's death and says he cannot ask for forgiveness. The Boylars respond saying Serling must put down the burden at some point. In the last moments of the film, it is shown that Walden was coincidentally the pilot who had evacuated Boylar's body after Serling's friendly fire incident.

Question: Who claims that Walden was a coward ?
Answer: Staff Sergeant John Monfriez (Lou Diamond Phillips) claims that Walden was a coward