Visible crew/equipment: When Hancock returns Embrey and his car back to his house just after saving him and then picks up and moves the car onto the drive, you can see the blue crane used in the reflection of the car windscreen.
Visible crew/equipment: White squared screens used for lighting are reflected on Hancock's glasses most of the time throughout the movie.
Visible crew/equipment: As the camera looks at the female cop pinned down, the crane used for the high fly stunts is reflected in the car's finish.
Visible crew/equipment: As the guys in the SUV look around, the studio lighting is reflected in their shades.
Visible crew/equipment: After waking up on the bench, Hancock puts on his shades. As he looks around, the studio light reflector is seen in his shades.
Answer: I saw it, too, and wondered. He's a street performer in L.A. that just happened to be around during filming. See: http://io9.com/5023487/hancock-giant-robot-mystery-++-solved.
johnrosa