Trump literally corroborates McGahn
“As has been incorrectly reported by the Fake News Media, I never told then White House Counsel Don McGahn to fire Robert Mueller, even though I had the legal right to do so,” Mr. Trump wrote on Twitter. “If I wanted to fire Mueller, I didn’t need McGahn to do it, I could have done it myself.”
Note the sort of double-negative here. It “has been incorrectly reported … I never told … Don McGahn to fire Robert Mueller ….” That’s an affirmation that he did tell McGahn to do it.