Desde o começo de The Deathly Hallows :
He shot another blocking jinx at them: the closest Death Eater swerved to avoid it and his hood slipped, and by the red light of his next Stunning Spell, Harry saw the strangely blank face of Stanley Shunpike – Stan –
Harry Potter and the Deathly Hallows, chapter 4 (emphasis mine)
Este rosto 'estranhamente branco' é visto em outros lugares como evidência da maldição Imperius (ou outros tipos de feitiços; poderia ser um feitiço Confundir, como abaixo):
Now Snape was head to head with Mundungus in an unfamiliar tavern, Mundungus’s face looking curiously blank, Snape frowning in concentration.
“You will suggest to the Order of the Phoenix,” Snape murmured, “that they use decoys. Polyjuice Potion. Identical Potters. It is the only thing that might work. You will forget that I have suggested this. You will present it as your own idea. You understand?”
Harry Potter and the Deathly Hallows, chapter 33
Eu diria que é a prova de que ele foi Imperiused / sob algum outro feitiço.