Visible crew/equipment: When they wheel Dianne (the OD) into the ER it's one long continuous shot from receiving to treatment 1, shot from the POV of the patient lying on the stretcher. As she's wheeled into treatment 1, the camera faces Johnny so we can see up the hallway behind him, and the entire admitting desk and waiting area are all blacked out, and there are two men, one of which (possibly the director) is sitting on a chair facing up the hallway where Johnny is and the scene is taking place.
Visible crew/equipment: When Squad 51 is dispatched to the car on top of a roof, it cuts to John and Roy driving in the squad as John responds to dispatch, and the reflection of the filming vehicle is visible on the squad's surface.
Visible crew/equipment: When Roy and Johnny are dispatched to the plant with an 18 yr old whose arm is caught in a machine, the outlines of the mic transmitters are visible on the left side of Johnny's shirt, when he's on the Biophone, and on the left side of Roy's shirt, when he's putting the tourniquet on the 18 yr old.
Visible crew/equipment: After Dianne's OD, once she passes out and Johnny begins to work on her and inserts the esophageal airway, the bulging outlines of the mic transmitter and wire are visible on the back of Johnny's shirt.
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 ★