Matt never has Pickett take off his hat to more closely examine his head for the white scar from his hairline to his eyebrow as stated on the wanted poster. The picture in the poster looks just like Pickett otherwise so you'd think Matt would ask him to take off his hat before giving him his gun and letting him go. His hat covers most of his forehead.
While the camera is showing the wanted poster, Matt reads it out loud, saying that the man has a small scar from his hairline to the left eyebrow. The poster doesn't say which eyebrow (although the picture does show the scar above the left eye).