Visible crew/equipment: After he stirs it, Det. Kinderman lifts the spoon out of his coffee as he starts to talk to Chris at the dinner table. A perfect reflection of the cameraman can be seen in the left of the spoon. (01:13:00)
Continuity mistake: Det. Kinderman talks to Chris as they're having coffee in the kitchen and says, "My opinion, he was killed by a very powerful man" and her right hand appears by her face between shots. (01:14:20)
Continuity mistake: Det. Kinderman throws his napkin down flat on the table in front of Chris as he gets up. In the next shot it has been rearranged on the table. (01:15:40)
Continuity mistake: Before she gets up from the table, Chris asks Det. Kinderman, "Would you like some more coffee?". His cup is obviously empty as she picks it up but if you look closely throughout this continuous scene, he's never touched it. (01:15:50)
Continuity mistake: After she gets up from the table, Chris walks into the kitchen and we see an oil and vinegar tray on the lower level of the shelf above the cutting board. We see this spot before behind Det. Kinderman as he looks at his coffee, and the oil and vinegar tray are not there. (01:16:00)
Continuity mistake: In the scene with the crucifix, Chris falls to the floor after Regan bashes her in the face. Look closely at the dresser that eventually comes sliding across the room at her. When we first see it, it's about half a foot to the right of the closet door on the left of the room, and is never touched or moved. When we see it again as it comes sliding across the room at Chris it's been moved to the left right up against the closet door. (01:19:10)
Continuity mistake: Chris first meets Damien on a bridge as two other people walk in front of him. In the next shot they're behind him. (01:19:40)
Continuity mistake: Chris walks with Damien after they meet on the bridge. As they talk she's smoking a cigarette, which she throws down and puts out with her foot. After she says, "How you go about getting an exorcism?" the cigarette is back in her right hand. (01:21:20)
Continuity mistake: Father Karras confronts Regan for the first time and just before she pukes on him fresh vomit appears on her night gown. Her eye makeup becomes darker and her hair is matted down also between shots. (01:25:35)
Continuity mistake: In the basement as Chris irons Father Karras' clean shirt, her cup on the ironing table rotates 45 degrees throughout the scene without being touched. (01:25:55)
Continuity mistake: At her front door, Father Karras asks Chris, "Did Regan know a priest was coming over?" as he looks at her. In the next shot he's looking down. (01:28:10)
Continuity mistake: As Father Karras listens to a tape recording of Regan at the university language lab we see the tape recorder running, a pen in his right hand and no ash tray or cigarette. In the next shot from behind smoke rises from a lit cigarette and the pen is on the desk. (01:29:15)
Continuity mistake: As Father Karras listens to a tape recording of Regan at the university language lab the lamp above his head is on his left. In the next shot it's right in front of him. (01:29:30)
Continuity mistake: Father Karras listens to a tape recording of Regan at the university language lab and there are three rows of seats in front of him. In the next shot from behind there are two rows in front of him. (01:29:35)
Continuity mistake: Damien brings a tape recorder to Regan's room and a brown/green plastic bowl is on the table to her left. In the next shot when the draw of the table pops out the plastic bowl is moved back about four inches. (01:31:10)
Continuity mistake: Damien starts the tape recorder in Regan's room twice between shots. (01:31:40)
Revealing mistake: When Father Karras sprinkles holy water on Regan, they forgot to paint her ear lobes and it looks terrible. (01:32:30)
Continuity mistake: Lots of stuff moves as Damien waits on the couch in Chris's living room as she pours him a drink. The flower pot on the back wall under the ceramic pumpkin moves to the left and the couch he's sitting on moves a couple of feet to the left. Later everything moves back. (01:34:00)
Continuity mistake: Damien plays the tape of Regan for the Language Lab Director and when we first see them a chair is in front of Damien. In the next shot the chair is gone and a coat appears next to him on his right. (01:35:30)
Continuity mistake: As the Language Lab Director plays the tape of Regan backwards for Damien he turns on the wrong tape recorder. There's no indication that this is not the first time he's heard the tape and he uses the recorder on the left to listen, and is not dubbing anything onto the recorder on the right. When we hear the backwards tape he uses the recorder on the right which does not have the right tape spooled up and doesn't have an overdub of the original to play backwards either. (01:35:40)
Answer: The demon wants everyone to lose hope for the girl and give up on her. Her father, having already flown the coop, just makes this goal that much easier.
TonyPH