Smoke Eater - S4-E16
Continuity mistake: When John and Roy are with the possible MI, while Roy's setting up the IV bag John's on the Biophone with Rampart, and after Brackett orders the IV TKO with MS, we see that Roy's pant leg has nothing on it, but then it cuts to the closeup and suddenly there are strips of torn tape (for IV as usual) on Roy's pant leg.
Smoke Eater - S4-E16
Visible crew/equipment: When Station 51 is dispatched to the 'structure fire', in the shot facing the squad as it starts to roll out, we can see the black tape covering the lightbar's chrome surface atop the squad, which also vanishes at the incident.
Smoke Eater - S4-E16
Continuity mistake: While John and Roy are treating the possible MI, when John's on the Biophone with Rampart his watch reads 5:10, but after the patient goes into V-fib John's watch reads 2:45.
Other mistake: All the guys are sitting around the table in the day room discussing how smart kids are, and when the tones drop we hear the dispatcher say, "Squad 51 possible assault victim," yet all the guys from the engine company rush off and head to the rig in the apparatus bay, even though only Roy and John were called.
Daisy's Pick Blind Date - S4-E7
Revealing mistake: When John and Roy bring the hypothermic patient into treatment 3, Morton uses the laryngoscope, but the problem here is that when it's placed we can see that the laryngoscope is actually at the side of the patient's face.
Other mistake: When Johnny brings the officer who was shot into the ER, as soon as he's loaded onto the gurney Carol takes his BP then tells Brackett his BP, but she also tells him that his pulse is 120, even though she never took his pulse. Additionally, when Morton places the blood vials on the tray and tells the nurse, "I want this sent to the lab STAT, type and cross match, and CBC and differentials STAT," due to the urgency of the situation, but the nurse doesn't leave, she just stands for the rest of the scene.
Continuity mistake: During the structure fire at Kiddytime Toy Factory, when the man is downed by an electrical shock, Johnny pulls out the defibrillator and Biophone from the squad, and in Johnny's closeups with the Datascope we can see that its center knob on the right is missing, but in the Datascope's closeups the knob is back.
Other mistake: When Squad 51 and the engine company arrive at the rock quarry, in the shot after John tells Jason to get the HT, just as Roy, Captain Stanley and Mike walk towards the right side of the screen, something drops down from the top of the screen, enough to cover the top left corner of the screen area, then gets pulled back up.
Continuity mistake: When Station 51 is dispatched to an 'unknown type rescue', the woman who opens the door tells them she didn't call, and when Roy asks her if he and Johnny can check on her sick husband, Roy's second shirt button is open and his undershirt is visible, but in the next shot it's buttoned up again.
The Wedsworth-Townsend Act - S1-E1
Continuity mistake: While Roy and John are at the boatyard searching for the girl's severed hand, when they walk into the mess of lumber neither of them can be seen in the other one's closeup, even though they both start looking around in the same spot, at precisely the same time.
Visible crew/equipment: During Squad 51's rescue of the hunter who was injured on the cliff, in the closeups of Copter 10's pilot, at the right upper corner of the screen above the windshield, we can see the edge of the white screen used to block the view through the windshield.
Other mistake: While Charlie is trying to figure out what's wrong with the squad, when Captain Stanley, Roy and John are sitting around the table, there's a can of scouring cleanser which has yellow tape covering the "a" and "x" so all we see is the "ja" on the can, in order to hide its brand name, which is Ajax.
Visible crew/equipment: When Johnny tells dispatch to respond Engine 51 to Oceanland Park, as Engine 51 pulls away from the curb, the shadow of production equipment is visible on the engine's surface and the street.
Visible crew/equipment: When Station 51 is dispatched to the possible heart attack, just as Squad 51 is leaving the apparatus bay and passing the exterior glass doors to Captain Stanley's office, the reflection of the location's array lighting is visible on the glass doors.
The Tycoons - S5-E23
Visible crew/equipment: After inspecting Davey's Dogs, when John and Roy head to the squad discussing how only a total idiot would buy the stand, the reflection of the location's array lighting is visible on the squad's surface, and the reflection of the camera dolly can be seen on the chrome spotlight.
The Tycoons - S5-E23
Revealing mistake: After Roy and Johnny get to the hospital with the 18 month old baby who stopped breathing, when Johnny is rushing up the hallway giving mouth-to-mouth to the baby, we can see that the happy little baby is wide awake and even smiling.
The Tycoons - S5-E23
Visible crew/equipment: When Roy and Johnny get back to the station talking about the ten fire inspections and two runs, the moving shadow of the boom mic is visible on the cabinets above Chet.
The Tycoons - S5-E23
Visible crew/equipment: During the fire at the chemical plant, a couple of shots after we see Captain Stanley walking between Roy and Chet as they're manning two hoses on the roof, we see a shot of Engine 15 as it heads toward the camera and then drives past it, and the reflection of array lighting is visible on the engine's surface.
The Tycoons - S5-E23
Visible crew/equipment: Just as Roy brings the victim with the heart wound into treatment 2, in the upper left corner we can see the moving shadow of the boom mic.
The Tycoons - S5-E23
Other mistake: When Johnny and Roy are in the kitchen talking about pooling money for Davey's Dogs, there are three small containers of milk on the table which have tape covering the brand names.
Answer: I believe you are speaking of the old man, Mr. Wilson. He's played by J. Pat O'Malley.
Bishop73
Correct, it was J. Pat O'Malley...he also played the grandfather with his grandson when their rocket exploded, and also played "Old Bill" in the episode with Ann Prentiss, where Gage saves the little girl from the burning tree house, and her mother falls in love with him.