The door chain on the front door of Pierce's house, clearly shown in episode one, is clearly missing in this episode.
When Pierce is explaining about Moretti's condition of not being able to recognize faces, we see him from the back as he takes a Red apple out of his bag and takes a bite. But when the camera switches around for the front view, he's holding and eating a Yellow one.
Characters refer to the interstate highways in Chicago by their numbers - 90, 94, 290, 55. Chicagoans refer to those highways by name: Kennedy (90 north of downtown), Edens (94), Eisenhower (290) Stevenson (55) and Dan Ryan (90/94 south of downtown). Even relative newcomers, if they do any driving in the metro area, quickly pick up on the names rather than the numbers.