Daisy's Pick Blind Date - S4-E7
Other mistake: When dispatched to the fire in the theater, the companies called are Station 51, Engine 85, and Station 36, but at the scene of the fire we see Engine 9 roll up and also see firemen with 19 on their helmets. These are shots from previous episodes including 3x7, "Promotion", when Roy and John rescue the security guard at the structure fire.
Other mistake: After Station 51 is dispatched to the 'vehicle accident with injuries', in the exterior shot as the squad and engine roll out, we can see the real Station 127's vehicle is still parked inside the apparatus bay, near the rear bay door.
Audio problem: After the sniper throws down the rifle, we see Captain Stanley start talking to Chet and Marco, though at first we don't hear anything, we then hear, "Put on your air masks, " but that is not Captain Stanley's voice we hear. Oddly enough, to me it sounds like John's voice. Have a listen.
Other mistake: When Station 51 is at the scene with the electrocuted man, he's dangling from a rope below the second stem of the letter H, in the large sign which reads "HOTEL", above the striped awning. In the shots from above the sign, looking directly down as they set up the ladder, we can see the letter H and the awning, but the dangling man is simply not there in the shots from this perspective, even though we should be able to see him.
Revealing mistake: At the structure fire at an abandoned building, when Engine 164 arrives we see that it has distinctive markings beside the driver's side door and tire rim. When Engine 72 arrives the same markings are in the same place, revealing that it's the same engine and they used different magnetic number decals for the engine.
Continuity mistake: In the ER staff lounge, when Early and Dixie are watching The Game, there are five books lying on the TV with all their binding facing the right side in the closeups, but in the wide shots the books are facing the opposite way, with binding facing the left.
Continuity mistake: When the injured photographer is brought to the ER, Dix says treatment 7 and we see them heading into 7's door (which is around the corner from treatment 4 and 5, and has no color lines that run past its door) in the shot from the hallway. However, in the next shot from inside the treatment room, we can see they're not in treatment 7, but actually in treatment 4, note the red, green, and yellow lines on the hallway floor in front of its doorway, and treatment 7 has no lines that run past its doorway. When Dixie, Early, and Brackett step into the hallway it's even more obvious.
Audio problem: When the guys reach the top of the tower ride at Oceanland Park, we hear Captain Stanley say, "Kelly, you go up on top and throw the tag line over the side, we'll take the stokes up that way," but Cap's mouth is saying something entirely different.
Family Ties - S6-E16
Other mistake: Before the fire in the patient's room, which is caused by liquid shorting out the clock radio, we can see the tape covering the brand names of the baby powder and the clock radio.
Revealing mistake: On the way to the basketball game against 16, when all the guys are pushing Chet's station wagon down the street, it's Kevin Tighe's double who is pushing the car, and he looks nothing like Kevin.
Continuity mistake: During the basketball game against 16, when Chet is finally in The Game at halftime, 51's side of the court is at the right of the screen, but in the closeups of Chet's shot going into the hoop - scoring, we can tell by the wall and backboard that a bunch of his baskets are actually going into the hoop on the other side of the court, behind him.
Revealing mistake: When the woman from the car accident is in the ER, she goes into V-fib, so Brackett, Morton, Roy and Johnny work on her and defib four times without success, and as we hear the hum of the flatlining, the camera pans to the left just low enough so that we can see her lying on the gurney, with her blue shirt still buttoned up.
Continuity mistake: When the woman from the car accident is in the ER, and goes into V-fib, Brackett, Morton, Roy and Johnny work on her. Johnny does chest compressions and they defib three times, then Morton takes over the chest compressions, but when Brackett is about to defib the fourth time we see Johnny's arms stopping the compressions, when in fact it was Morton doing them at that time.
How Green Was My Thumb? - S3-E17
Continuity mistake: Before they bring in the young girl who fell (with a dog bite), Dixie tells Brackett that she'll set up for her in treatment 1, and after Squad 95 brings her in, when Brackett and the paramedic (Donald Mantooth) leave the room we see that she is indeed in treatment 1, which is beside receiving. However, when Brackett takes the parents to see her, they go through the door that's between the double doors and treatment 2, which are on the opposite side of the hallway from treatment 1. Then in the next shot they're back in treatment 1.
How Green Was My Thumb? - S3-E17
Revealing mistake: When Roy brings in the man with the laryngeal obstruction (partial dental plate), Morton and Early meet them at receiving, then as they rush the stretcher into treatment 1, it's amusing to note that the treatment room across the hall (treatment 2) has room number 412 on it, and even better, treatment 1 itself has number 411 on its door. Obviously the set was prepped for the following shots, when Johnny follows the nurse onto the 4th floor.
Inventions - S3-E22
Other mistake: When Station 51 responds to the incident of the man who fell through the ceiling at his mother's house, the footage of the squad and engine pulling up to the curb of the house is from episode 3x15, "Messin Around", when they rescue Old Bill after he's collapsed in his house.
Revealing mistake: When Cindy and her mother come to see the station, Cindy goes to the closet with the gear, and as she opens the door Cindy starts laughing before Johnny even gets hit by the phantom, and then she glances toward the camera grinning because of the prank.
Other mistake: After Johnny gets hit by the phantom in the apparatus bay, Station 51 is dispatched to an unknown type rescue at 617-1/2 Kimball Rd, and before the dispatcher even gives the address, Mike has already located the area on the map with his finger.
Visible crew/equipment: While the guys are at the table eating Marco's stew, when Johnny remembers that he spent $8.42, numerous set lights are reflected on the coffee pot's chrome surface.
Revealing mistake: When the guys are in the backyard with the woman who fell through the ground into an old abandoned well, in the overhead shot we can see the cuts that created the cutout hole on the flat surface around her, and that it's not really dirt or sand that she's slipping through.
Answer: I was rewatching a few first season episodes of Charlie's Angels (1976), and in S1xE6 "The Killing Kind," I recognized the same actor. So, to finally fully answer your question, the two baseball players in School Days are played by Rod Perry and Sean Fallon Walsh.
Super Grover ★