Visible crew/equipment: When Early and Dixie are in the treatment room with Jenny, after Early asks Jenny if she can move her legs, the moving shadow of the boom and mic are visible on the wall behind Dixie.
Continuity mistake: When Roy finds Bonnie in the back seat of the wrecked car, Paula's luggage flips itself around and upright between shots.
Visible crew/equipment: At the scene of Paula's traffic accident, when Captain Hammer stands in Engine 51's cab and tells Marco to get the reel line, the reflection of equipment and set lighting are visible in the chrome surface of driver's side spotlight.
The Wedsworth-Townsend Act - S1-E1
Continuity mistake: When Roy and Johnny are with the tunnel worker who's in V-tach, the lights go out in the tunnel and Roy places one of the lanterns on the Biophone, but in closeups of the Biophone the lantern has vanished, then the lantern is back again once they've defibbed successfully.
The Wedsworth-Townsend Act - S1-E1
Continuity mistake: When Roy's on the Biophone with Brackett, after telling him that Dix is one of the victims, Johnny reaches out and takes the receiver from Roy with his left hand, but in the next shot he's taken the receiver with his right hand.
The Wedsworth-Townsend Act - S1-E1
Visible crew/equipment: At the very start of the episode, as the camera slowly passes the vehicles and the posts, the moving shadow of the camera is visible on one of the posts at the left as it moves past it.
Continuity mistake: When Roy tells the other guys of 51 what they need to do to rescue the doctor, once they're in the hot room, in the wide shot Roy's holding the handie-talkie in his right hand as he's gesturing with that hand, but when it cuts to Roy's closeup the HT has vanished from his right hand, as he's still gesturing.
Continuity mistake: After John makes a sarcastic comment, while he and Roy are in the treatment room with Dr. Early, Roy takes the squad's oxygen tank with him when he leaves the room, but when he exits the ER to get into the squad, the oxygen tank is gone.
Character mistake: When Roy and Johnny are waiting outside the radioactive lab, Roy sends Marco and Mike to replace Chet and the captain. When Chet and the captain come out, the captain points to Chet and then points up the hallway, while he says "All right, take off you two," even though it's only Chet who's heading outside to be decontaminated, and he could not have meant, "All right, take off you too," for the same reason.
Visible crew/equipment: A few shots after Johnny informs Brackett of the victim of the radiation incident, there's a shot of the ER with two orderlies pushing a gurney towards the camera, and the two actors' tape marks are visible on the floor at the bottom of the screen, just before Brackett and Dixie stop there, when Brackett tells Dix to notify the radiation security guard.
Continuity mistake: When Johnny and Roy go into the radioactive lab, Johnny removes his glove to check the doctor's carotid pulse and when they walk through the doorway both his gloves are off (he's holding them), but in the next shot exiting the doorway both of Johnny's gloves are back on.
Visible crew/equipment: After Roy helps the looter into the squad, when Johnny goes to the motorcycle and finds the leather bag full of jewelry, the mic wires that run from under his shirt/belt into his right pants pocket (with the transmitter bulge) are visible as he bends down.
Visible crew/equipment: After the looter is helped into the squad, just as Roy gets into the driver's seat, the reflection of camera equipment becomes visible on Squad 51's vent window (not to be confused with Roy's arm or the reflection of the red wing mirror).
Revealing mistake: After Squad 51 is dispatched to the motorcycle accident, there are wide shots of the squad driving through the hills, then in the closeups of Roy and John, the squad shakes from side to side to mimic driving, but we can see that the surrounding rocky area behind the squad (matte painting) does not actually change at all.
Continuity mistake: When Squad 51 is dispatched to the heart attack, when Roy opens the apparatus bay door John and Bonnie run underneath, and we can see that Engine 51 is not parked in the bay, but in the exterior shot of the squad pulling out the engine is in the bay.
Continuity mistake: When Roy and John leave the ER after the baby delivery, the base station dispatches them to the motorcycle accident, and in the next shot as the squad turns the corner, there are three people in Squad 51, we see Roy, Johnny and someone seated between them, while they're en route.
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 ★