You can't possibly prove that.
There is no proof that Butler even met with President Lincoln on the day in question.
Walt
Show it to me. Or do you believe that they did, and 'neo-confederate' revolutionaries have somehow erased it from the historical record? There is not a single record of someone back then disputing Butler. Not a letter, not a statement, not an article, nor even a comment in a book, that disputes Bulter's record of their conversation. Not to my knowledge anyway. If you know of one, show it to me.
There is no proof that Butler even met with President Lincoln on the day in question.
According to the 'Collected Works of Abraham Lincoln', Ol' Abe directed Butler to meet with him about that time, but you know that.
That's a lie. The meeting is documented in the index of Vol. 8 of the Collected Works of Abraham Lincoln ed. by Basler. Listed is an April 10, 1865 memo from John Hay scheduling a meeting between Butler and Lincoln for the next day. You have been informed of this memo repeatedly, Walt, and therefore have no excuse for fibbing about Butler's meeting.