Continuity mistake: When Chet is brought into the ER after being thrown in the explosion, Johnny is empty handed, but when he leaves treatment 1 with Dix, the HT is suddenly inexplicably in his hands.
Continuity mistake: During the actual rescue of the boy from the overturned car in the water, Roy's, Johnny's, and Chet's shoes are water-type shoes, which then change back to their uniform shoes.
The Lighter-Than-Air Man - S5-E8
Visible crew/equipment: When Johnny brings in the box and Chet removes the wrapping for the baby layette, note the unfinished set wall past Engine 51 in the apparatus bay, which we can see since the front bay door is open, but when Captain Stanley walks in telling John about the phone call, the front bay door is now closed, then when the tones drop that set wall can be seen once again.
Pressure 165 - S5-E7
Visible crew/equipment: When Roy and Johnny are with Chef Michel, the outline of the mic transmitter can be seen on the front of Johnny's shirt.
Continuity mistake: While Roy and John are still aboard the Coast Guard helicopter during the cliff rescue at Catalina Island, when the chopper's on scene, in the overhead shot from inside the chopper, we can see where the victim is lying on the rocks, however, in the next shot from ground level, the victim is now lying on the other side of the jutting rock.
Continuity mistake: While Early, Morton, and Dixie are examining the young boy who fell, Early's wearing a gold ring (wedding band in real life) on his left hand's ring finger, but when Dixie finds the tick she asks Early to have a look, and in the closeup of the boy's head, Early's gold ring has vanished.
Continuity mistake: When Engine 8 is dispatched to "man unconscious at construction site," we see Engine 8 going past Curson Ave, then the next shot Engine 8 is driving up from the other direction of Curson Ave and passes it going the other way. Neither are flipped shots. Other than seeing the sign for Curson Ave, other giveaways are the same signs or parked vehicles.
Other mistake: When Squad 51 is dispatched to an 'unknown type rescue', as the squad rolls out we can see the Crown engine from the show's first two seasons parked in the apparatus bay, instead of 51's current Ward LaFrance.
Visible crew/equipment: When Roy tells Karen that she'll know when she can do it on her own when she'll have to, the reflection of set lighting is visible on the squad's chrome spotlight. Additionally, when Station 51 is dispatched to the structure fire the rear bay door closed, but when the rigs roll out the rear bay door is open.
Other mistake: When Station 51 is dispatched to the landslide, the engine company get into their turnouts and roll out, but in the next exterior shot as the engine drives past the camera, not only are the guys not in their turnouts, it's too obvious that none are 51's guys, and the one in Chet's jumpseat even leans forward. Presumably they're 127's guys. Also the light bar on the squad and the rotating light on the truck are not on.
Other mistake: When Station 51 is on scene at the landslide, there's a dresser on the grass in front of the house, and when the explosion occurs due to the broken gas main, in the closeups as Johnny dives to the ground there's what looks like a can of gasoline (used for the stunt perhaps) atop that dresser that wasn't there before, and it's also not in the wide shots as Johnny dives down.
Visible crew/equipment: After Roy and Johnny speak to Chet's friend the realtor, when Station 51 is being dispatched to the accident on Harbor Freeway, in the overhead shot of the apparatus bay, we can see the shadow/reflection of production equipment moving on the engine's windshield.
Visible crew/equipment: When Station 51 is dispatched to the rescue on Johnson Canyon Bridge, just as Engine 51 rolls out of the apparatus bay, the reflection of array lighting and two reflector screens are visible on the engine.
Above and Beyond... Nearly - S5-E20
Visible crew/equipment: In the dental clinic, when the possible MI is being examined, two actors' black tape marks become visible under the patient's chair, one below the footrest and another below the headrest.
Other mistake: After Brackett tries unsuccessfully to get O'Brien on the line to ask about the fish tank, it cuts to an exterior shot of Station 51, and we hear the dispatcher say, "All units responding with Engine 3 cancel," but subtitles read, "Four units with Engine 3 cancelled." Subtitles from Universal Studios 2010 DVD.
Other mistake: When the man injured in the manhole is brought to treatment 6, Early tells Roy to patch him up for an EKG, but the subtitles read, "Patch one from the EKG," and then Early tells the x-ray technician to do a skull and chest series, but the subtitles read, "Skull and chest searches." Subtitles from Universal Studios 2010 DVD.
The Girl on the Balance Beam - S5-E18
Visible crew/equipment: When Brackett and Morton go to the outdoor eating area to speak with Nancy's father, just as Brackett sits down and crosses his legs, the actor's T-mark is visible on the floor in front of his chair.
Continuity mistake: When the unconscious boy is brought to the ER, he's taken into treatment 2, with a windowless door, but when Early is doing the lumbar tap on the boy, the door behind Early has a window, and also by the way the room is set up, we know it's treatment 1 he's in, not 2.
Continuity mistake: At the restaurant, when they begin to work on getting Mrs. Merkle out from under the car, Vince sets the Biophone down on the table, and there's a netted, red glass candle on the table, but in a following closeup the candle's net has vanished and it's pinkish clear glass now. Other items on the table change as well.
Continuity mistake: When Ruthie is wheeled into the ER, Dixie tells the attendants to put her in the treatment room where Dr. Early's waiting, and they wheel her into treatment 2 which has a windowless door, but when they're in the room the door has a window, which means she's in treatment 1, not 2. Plus the fact that both treatment rooms are set up differently.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy