Visible crew/equipment: In the ambulance, when Roy administers the bicarb and then the isoproterenol IV, the outline of the mic transmitter is visible on the left side of the third paramedic's shirt, as he's doing chest compressions.
Continuity mistake: During Johnny and Roy's flight to LAX there are a few shots of the airplane in mid-air and when it lands, and the type of airplane changes - note the engines and tail.
Visible crew/equipment: At the start, when Johnny is telling The Stewardess about the underwater rescue and in following shots, the outline of the lavalier mic wire and the dark strap (that holds the transmitter) around Johnny's waist are visible on the back of his shirt, and the mic transmitter is visible on the front, left side of his shirt, above his belt.
Visible crew/equipment: After the airplane rescue, at Rampart when Brackett congratulates Roy and Johnny on a job well done, the outline of the mic transmitter is visible on the front, left side of Roy's shirt, just above his belt.
Continuity mistake: When transporting the heart attack victim from the plane the ambulance starts as a Ford and ends as a Chevy.
Continuity mistake: Marco's mustache goes missing when Station 51 is dispatched to the structure fire, but then it reappears.
Visible crew/equipment: When Johnny removes David's red helmet after his motorcycle accident, the reflection of array set lights are visible on the red surface.
Visible crew/equipment: At training center, after 18's guy falls into the trench with the sulfur trioxide, as they're removing his turnout coat just as Roy opens the drug box, seen behind Marco are four crew members who are near the tanker with the sulfur trioxide, past the trench.
Continuity mistake: When Dixie shows Johnny the newspaper, Johnny reads the ad aloud which states, "Wanted, 1925 Paige fire truck, $25,000, if in mint condition," and Johnny says that it is exactly what the ad submitter wants. The "it" being Roy and Johnny's refurbished fire truck. The problem is that in 3x2, "The Old Engine," when Johnny and Roy are telling Chet and Marco about their purchase, Johnny says that it's a 1932 Dennis, and when they're looking it over, the blue "Dennis" emblem is attached to the hood of the engine.
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: When Squad 51 arrives at the training center, Johnny's turnout coat is open and we see that he's only wearing an undershirt, but when it's 18's turn at the sulfur trioxide, as Johnny's putting on his air mask he's wearing the blue uniform shirt under his turnout.
Visible crew/equipment: When Engine 51 and Squad 51 arrive at the training center, Captain Stanley opens the door then steps off the engine while Chet climbs down from the jumpseat, and the location's array lighting is reflected on the door's window.
Continuity mistake: During the actual rescue at Catalina Island, Johnny and Roy are now wearing water-type shoes, not their uniform shoes.
Deliberate mistake: When Johnny and Roy are on the Coast Guard copter, responding to 'victim down at cliffs at Catalina Island', there are four closeups of the guys looking out the windows which are flipped shots - note their uniforms are backwards, the paramedic patches are on their right sleeves instead of their left.
Visible crew/equipment: When the man, who walked in with his daughter, has a heart attack at Station 51, while he's lying on the floor in the apparatus bay we can see the top of the set, the part of the ceiling that's incomplete.
Other mistake: When Roy and Johnny help free the man whose arm is trapped in the pipe, just as the man stands up we can see the boxes of detergent on the shelf behind him, with their brand names covered with black tape.
Revealing mistake: When Station 51 is dispatched to 'man trapped', just as Engine 51 rolls out of the apparatus bay and heads down the driveway, the real 127's vehicle is seen parked inside the bay, near the rear door.
Continuity mistake: After bringing the man who choked on a beer can's pull tab to Rampart, when Squad 51 returns to the station and backs up the driveway, the engine seen parked in the apparatus bay is the Crown from seasons 1 and 2, not their current Ward LaFrance engine.
Continuity mistake: After examining Tommy, when Brackett speaks to Mrs. Lawson, the boy's mother, her handbag is hanging off her shoulder in all the shots facing Brackett, but in all the shots facing Mrs. Lawson the bag is gone.
Revealing mistake: After the MI patient from the construction site is brought to treatment 1, when Early uses the laryngoscope for an endotracheal intubation, we can see that he merely places the laryngoscope at the side of the man's face, especially since we can still see the entire distal end beside the man's neck.
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.