Wikileaks already has their "official" version of Miller's resignation on the resignation.
JAMES MILLER, JR.
Resignation from Defense Science Board[edit]
On June 2, 2020, Miller resigned from the Defense Science Board in protest after troops used tear gas and rubber bullets to disperse lawfully assembled protesters outside of the United States White House who refused to disperse when attempting to restrict the movement of President Donald Trump, accompanied by U.S. Secretary of Defense Mark Esper, as the President walked to the St. John's Episcopal Church across from the White House.
In an open resignation letter to Esper, Miller cited the United States Uniformed Services Oath of Office that he had taken to "support and defend the Constitution of the United States," and wrote that Esper and Trump had violated the same oath, writing:
President Trump’s actions Monday night violated his oath to “take care that the laws be faithfully executed,” as well as the First Amendment "right of the people peaceably to assemble." You may not have been able to stop President Trump from directing this appalling use of force, but you could have chosen to oppose it. Instead, you visibly supported it.
Anyone who takes the oath of office must decide where he or she will draw the line: What are the things that they will refuse to do? Secretary Esper, you have served honorably for many years, in active and reserve military duty, as Secretary of the Army, and now as Secretary of Defense. You must have thought long and hard about where that line should be drawn. I must now ask: If last night's blatant violations do not cross the line for you, what will?
Miller also criticized Esper's statement urging state governors to "dominate the battlespace," writing: "I cannot believe that you see the United States as a 'battlespace,' or that you believe our citizens must be 'dominated.' Such language sends an extremely dangerous signal."
Miller is very disingenuous
Another ones bites the dust (sleeper), James Miller.