Continuity mistake: When the squad rolls up on the OD victim's residence Roy drives the squad over the little fence and bends it. When he takes off the gate is back in its original position.
Visible crew/equipment: At the structure fire, when Squad 51 stops at the hydrant to lay the dual lines, as Engine 51 drives past the squad, the reflections of array lighting and the reflector screen are briefly visible. Then when Engine 51 rolls up to the fire, as Captain Stanley tells dispatch to send a second alarm and approach from the west, we can see the reflection of a crew member wearing a long sleeved white shirt and dark slacks, in the window behind Captain Stanley. He's still visible when Squad 51 pulls up alongside Engine 51, and also when Cap tells Engine 9 to lay duals.
Visible crew/equipment: During the structure fire, in the shot after Johnny runs up the ladder to the roof to get to Captain Harmell, a crouching crew member can be seen under the open passenger side door of Engine 17.
Revealing mistake: At the structure fire, when Engine 9 and Engine 17 roll up, we can see the large, red, rectangular vinyl material that is adhered to the front of the engines, with their company numbers printed on it. Additionally, the red vinyl material adhered to the top of 9's and 17's cabs, which cover their real company numbers, flap up in the wind.
Continuity mistake: After 17's Captain Harmell has fallen through the warehouse roof, when Roy wraps the tape around Harmell's leg splint, the entire splint is covered by tape when they lift him up the ladder, but when Harmell is carried out of the snorkel, there is much less tape - it's wrapped around the splint only 5-6 times.
Continuity mistake: When 51's guys are at the back of the station with The Old Engine, Johnny tries cranking it and his watch reads 5:20. Then after Squad 51 is dispatched to the heart attack, when Johnny's on the line with Rampart after defibrillating the patient his watch reads 11:15, then after administering atropine, his watch reads 2:30.
Continuity mistake: When Johnny and Roy walk into Councilman Wilby's home, Wilby's wearing a buttoned up shirt and tie, and they place the O2 tank near his feet, but in Wilby's first three closeups the O2 tank is already behind the couch by his head and his shirt is unbuttoned with no tie, but in the wide shots Roy and Johnny haven't even made those changes yet.
Visible crew/equipment: When Engine 51 gets dispatched to their first run on the new Ward LaFrance engine, Captain Stanley tells Johnny and Roy to get their gear to go with them. When the paramedics go to the closet to get the turnout coats, the bulging outlines of the mic transmitters and wires are visible on the sides of their shirts before putting on the turnouts. The outline of Johnny's mic transmitter is also visible when he first walks over to the new engine.
Visible crew/equipment: When all the guys get back to Station 51 and walk quietly to see the cat on Johnny's bed, the actor's black tape mark is visible on the floor beside the bed.
Visible crew/equipment: During the boating accident rescue, the outlines of the mic transmitters and wires are visible on the backs of both Johnny's and Roy's shirts, on their right sides.
Visible crew/equipment: When Roy gets the little girl, Angie, out of the wrecked airplane and then places her in the Stokes basket, the outlines of the mic transmitter and wire are visible on the back of his shirt.
Other mistake: On scene at the plane crash, just as Roy and John are about to head down to the aircraft we hear the dispatcher ask, "Foam 23, what is your location?" but the odd subtitles read, "Phone 23..." Subtitles from Universal Studios 2010 DVD.
Character mistake: After the cat has her kittens, when Squad 51 is dispatched to the 'man trapped in boating accident', we hear Captain Stanley respond, "Station 51, KMG365," even though his response should have been, "Squad 51, KMG365," since it's only John and Roy that were dispatched, not the entire station.
Visible crew/equipment: When Johnny works on the woman in the airplane wreck and says that he'll get the radio, and then when Johnny gets into the ambulance with Angie, the outline of the mic transmitter is visible on the back of his shirt. Additionally, while Angie's mom is being loaded onto the ambulance, the outline of the mic transmitter is visible on the side of Angie's top.
Continuity mistake: During boat rescue, when Johnny's on the Biophone with Rampart, right after Brackett tells them to continue oxygen and maintain D5W IV, Roy has his hand out with the IV bag and tells 81's guy to hold it, but in the next shot 81's guy is taking a BP cuff from Roy's hand, not an IV bag.
Continuity mistake: When Station 51 is at the scene of the plane crash, in the long shot Roy climbs down to the wrecked plane and tosses his helmet, but wears his gloves when he starts looking for survivors, then in the next closeup his gloves have vanished.
Continuity mistake: When Roy and Johnny are on scene at the boating accident, John contacts Rampart, and in the closeup of the base station telephone, we see the old reel-to-reel tape recorder that was used during season 1, behind the old GE Deskon 3-button telephone. In the next shot Rampart's base station is back to normal.
Continuity mistake: When the stokes with the boating accident victim is being loaded onto the Harbor Patrol boat, Roy's standing behind The Boat in the water and Johnny's in The Boat with the stokes, but in the next shot they've switched places, Roy's in The Boat and Johnny's behind The Boat. Others have also switched places between shots.
Continuity mistake: When 51's guys are standing around Johnny's bed looking at the cat, in the cat's closeups she is facing the locker room, but in the other shots she is facing the opposite way, with the guys behind her.
Visible crew/equipment: After Station 51 is dispatched to 'man trapped at the rock quarry', when Squad 51 heads through the tunnel-like passageway on the right, it cuts to a shot from behind Mike who's driving Engine 51, and just as the engine heads through the left passageway, we see Squad 51 on the right, and can also see the top of the camera and the other cameraman covered in a dark blanket at the back of Squad 51, as he shoots the footage from that angle.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy