Updated on Oct. 18 a 1:15 p.m. ETThe pushback — and the outrage — began immediately.Trump was asked on Monday why he had not yet commented on the deaths of four U.S. soldiers who were ambushed during a mission in Niger on Oct. 4. In his answer, Trump turned attention to the policies of past presidents and their contact with families of service members who have died.On Tuesday, he followed his initial comments with more assertions, offering a specific example. That prompted further rebuttal from staff of previous administrations.Meanwhile, a congresswoman said Trump told the widow of one of the soldiers killed in Niger that he "must have known what he signed up for."Rep. Frederica Wilson, D-Fla., tells NBC6 that she overheard the call to Myeshia Johnson on Tuesday on a car speakerphone, as the two women were heading to Miami International Airport to meet the body of Johnson's husband, Sgt. La David Johnson.In a tweet Wednesday morning, Trump denied he said that, calling Wilson's account "fabricated" and adding, "I have proof." He did not say what proof he has.But by midday Wednesday, the soldier's mother, Cowanda Jones-Johnson, had backed up Wilson's account. She said she was also in the car listening to the call and told The Washington Post, "President Trump did disrespect my son and my daughter and also me and my husband."Ata Rose Garden news conference on Monday, a reporter had asked Trump: "Why haven't we heard anything from you so far about the soldiers that were killed in Niger? And what do you have to say about that?"The president responded, "I've written them personal letters."But as he continued, his response got less clear."They've been sent, or they're going out tonight, but they were written during the weekend," Trump said.Then came a promise of more."I will, at some point during the period of time, call the parents and the families — because I have done that, traditionally," he added. He spoke of how making such phone calls is a "difficult thing."Then came the moment that is vintage Trump. He turned it into an attack on his predecessors in office."If you look at President Obama and other presidents, most of them didn't make calls," he said. "A lot of them didn't make calls."The facts simply don't support such a statement.Trump's words prompted measured responses from the offices of the past two presidents.A former Obama White House official told NPR on Monday, "President Trump's claim is wrong. President Obama engaged families of the fallen and wounded warriors throughout his presidency through calls, letters, visits to Section 60 at Arlington, visits to Walter Reed, visits to Dover, and regular meetings with Gold Star families at the White House and across the country."On Tuesday, George W. Bush's spokesman wrote in an email, "I don't have a statement from President Bush; I can only confirm that of course he wrote, called, and visited privately with hundreds if not thousands of families of the fallen."Twitter was also full of reaction from former Bush and Obama White House staffers, including photographs and emotional stories of meetings with soldiers' families at Walter Reed National Military Medical Center in Washington, D.C., and of the former commanders in chief being present for the arrival of the remains of soldiers at Dover Air Force Base in Delaware.Many also used social media to share former President George W. Bush press secretary Dana Perino's past recollections of visiting troops and their families in the hospital — some were gravely wounded; some wouldn't survive their injuries. In April 2015, Perino shared that scene with NPR's Morning Edition: