No, it is not.
"Congress demanded Lee’s arrest, trial and execution. President Andrew Johnson, on his political honeymoon, was in favor of it. There was widespread support. But General Grant was enraged. He had given his word. It was
his name on the parole: put down your arms, go home and fight no more. We will not harm you.
Robert E. Lee had done just that. His parole had not been violated.
Grant insisted that he was not a politician, and admitted that President Johnson and Congress could do as they liked. But he added that the “parole” came under military law, and that he, as General of the Army, had pledged his word, and he aimed to keep it. He stressed that General Lee had scrupulously kept his word as well.
Then Grant quietly said that if charges were pressed, he would feel compelled to resign as General of the Army. His own sense of honor would be violated. This was a blow to the new President. Ulysses S. Grant was the most famous man in the country, and perhaps the most highly regarded. Johnson, who would face many problems and crises during his tumultuous administration, could not afford to lose the support and good will of the popular General. It was also not a battle he chose to fight.
The matter of a trial for Robert E. Lee was left to lie and eventually die. No further discussion of arresting and possibly executing General Lee was pressed. If Lee ever knew that Grant had put his personal prestige and honor on the line for him, it is unknown."
https://featherfoster.wordpress.com/2014/05/28/general-grant-saves-general-lee/