Continuity mistake: During the press conference at the U.S. Open where Roy begins to list the companies who are sponsoring him, he says that one of them is "Woody's Smokehouse" when the patch on his jacket says "Wally's Smokehouse".
Continuity mistake: When Roy is talking to Romeo about winning the U.S. Open he is seen with a glass of milk in his hand in one scene and in the next the glass in on the table in front of him.
Continuity mistake: When Molly comes for her first golf lesson, Costner takes the last bite of his hot dog. In the next scene, he still has some of the hotdog left.
Continuity mistake: When Roy and Romeo buy back his golf clubs from the pawn shop, the towel on the gold bag keeps changing positions as they are walking and talking.
Visible crew/equipment: When Roy is first practising at the U.S. Open you can see cue cards in Romeo's sunglasses a few times.
Other mistake: When Roy is about to hit the ball off the porta-potty, the TV commentator bets Romeo that he won't hit the shot onto the green. Roy's shot ends up on the fringe of the green, not on the putting surface itself (an important difference), but Dewey collects the bet.
Continuity mistake: When Roy is talking to Molly after their therapy session, the magazine Roy is reading disappears in one shot and then it's back in the next.
Audio problem: At the end of the movie when Roy finally makes the shot, The scene cuts to Molly on the side and she has her mouth open as she's screaming, but you hear her voice saying "I LOVE YOU".
Revealing mistake: In the scene where Romeo and Roy snap all the clubs other than the 7-iron, Roy drops his golf ball onto the grass. However, when he hits the ball, a white tee can be seen travelling up towards the top left of the screen. The tee can easily be seen but is much clearer in slow motion.
Continuity mistake: The first lesson Molly has with Roy, it's already dusk, and when they go outside, it's dark. At the end of the lesson, Roy says "Same Time Next Week?" and Mollie says "Okay." But then in the next lesson Mollie complains that he is late. But when he does show up for that late lesson, it appears to be in the late afternoon, not even close to dusk.
Continuity mistake: During the scene in the final round where Roy and David hit their balls onto a green, there are a couple of mistakes (one mistake has already been noted in this scene - the mistake where Roy is swinging his putter from side to side etc). Firstly, as they all walk up to the green, Roy's ball (which should be quite close to the hole) is not on the green. Secondly, when Dave misses his putt, look at Romeo. He is standing to the right of Roy, but in the immediate next shot he is on Roy's left.
Continuity mistake: When Molly goes to see Roy when he is wearing all that golfing equipment, when they go to sit down at the table Roy can be seen taking off the blue arm band and when the camera pans back for a wider shot, he is seen taking it off again.
Continuity mistake: In the scene where Molly comes to visit Roy in his winnebago, her hairstyle changes from minute to minute.
Continuity mistake: In the scene where Costner is playing Johnson in the final round, we see both of them lining up their putts. Costner is swinging the grip of the putter from side to side in front of his face. When we see him through Rene Russo's periscope, he is not moving the club at all. The shot cuts back to Costner, and he is swinging the club again.
Continuity mistake: When Molly goes to see Roy when he is wearing all of the golfing equipment, they walk outside and Roy pushes the lid of the ballcap he is wearing to the side. The camera angle changes and you now see the lid is facing straight back.
Continuity mistake: During the competition in which Roy is caddying for David Sims we see Roy about to hand Sims the three Iron. Notice that he has the golf bag on his shoulder. Then when Sims approaches him to ask for the seven iron the camera changes angle and the bag is now standing on the ground.
Continuity mistake: When Renee is talking to her mentor on the phone she begins by "doodling" a spiral from top to bottom on the note pad in front of her. Later you see a full shot of the pad and there are only small doodles at the top of the page, nothing in the middle. Again later you see the note pad with more doodles on it but they don't match the action shown at the beginning of the phone call.
Continuity mistake: During Molly's first golf lesson we see Roy about to show her how to swing the club. Right from the moment after which she takes her shot to where we see him take his, his hair changes styles during all of the different shots. This is particularly noticeable with his fringe.
Continuity mistake: When Roy goes to see Molly at her office we see him about to ask Molly out. During this scene Roy's hair style constantly changes. His fringe is messy and sticking up when the camera faces him from Molly's view; and flat and tidy when the camera is at the opposite angle.
Factual error: On the final hole, the shot that Roy "has" to make is hit perfectly the first time. For some unknown reason, it spins backward off the green. This is patently impossible with a 3-wood. The club just doesn't allow it, and any golfer on the face of the earth knows it. This scene should have been shot with a long iron, a 2 or 3 iron, which is still very hard to hit, but at least possible (for a pro) to put enough spin to back it up.