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: 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: 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: 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: After Kevin Costner plays the first round of the US Open when he plays horribly, he and his caddie are seen looking at his score being posted on the scoreboard. The number posted for the 18th hole is a 5. Later on, however, when he is talking to Don Johnson in the bar, and Johnson asks him, "How the hell did you shoot an 83?" he replies, "I missed a 5-foot putt on the last hole for an 82." Considering that the announcers say several times that he hit his second shot on number 18 in the water every single day of the tournament, this is impossible. If he hits it in the water, he takes a penalty shot and now he is hitting his fourth shot onto the green, putting for a 5. If he then, as he says, misses the 5 foot putt, he must make a 6 on the hole. I've watched it a thousand times, it just isn't possible.