As Carrie and her father sit down at 6:00 Arthur puts his pillbox to his right. After the cut the box is on the table to his left.
Doug fakes a phone call using his cell phone, when he leaves the room he leaves the cell on the table beside the couch. After Carrie comes home she makes Doug come back into the house and Doug then gets the cell out of his pocket to fake another call. Of course he has no opportunity to get the cell from where he left it previously.