Visible crew/equipment: When Brackett and Early are in Rampart's staff lounge discussing J.P. Dumont, Brackett agrees to let Early use his charm in the case, and when Early stands up an actor's small T-mark is visible on the floor, where Brackett was standing moments earlier.
Continuity mistake: When John first explains how to rescue the little girl in the hole, he wraps his left hand around his right wrist, but in the next shot it's his right hand that's around his left wrist.
Other mistake: When Johnny is complaining about Tom Wheeler while the guys are preparing lunch, Squad 51 is dispatched to a structure fire so Roy and Johnny head out of the kitchen, but Marco turns the stove flame off and the rest of the guys in the engine company leave the kitchen as well, even though they were not dispatched.
Other mistake: After Johnny gets off the phone with Tom Wheeler, and starts complaining about him while the guys are preparing lunch, there are two milk containers on the table which have orange tape covering the brand names.
Audio problem: After Tom Wheeler and his partner Kirk show up to assist with the trapped girl, when it cuts to Roy down in the rescue shaft we see him ask Johnny, "Do you see her yet?" but we don't hear any audio, just before we hear Johnny say, "We're getting close." Additionally, earlier at the start of the little girl's rescue, when Johnny tries to loop the rope around Helena's wrist and it doesn't work, he says,"Damn it," but the subtitles read "Darn it."
Continuity mistake: While John's lying in the lateral tunnel when digging to reach Helena, his entire uniform is covered in dirt, but when John pulls her out and is with Roy in the rescue shaft, John's uniform is only a little dirty, nowhere near as filthy as it was just moments before.
Visible crew/equipment: When John and Roy are tunneling through to the little girl trapped in the hole, they're in the second larger hole that has been shored up on all sides with wood (to keep it from collapsing), but when Roy points the chrome flashlight down the lateral hole Johnny's digging in, we can see in its reflection that the fourth wall doesn't exist, where the camera and lights are located.
Revealing mistake: On scene with the little girl trapped in the hole, when they shine the flashlight down the hole in the overhead closeup, it's too obvious that it's a doll with its arm raised up, plus the fact that we see plenty of space around the doll, contradicting the plot of the little girl being wedged in a tight space.
Revealing mistake: When Johnny and Roy are on the schooner, with the unconscious man hanging upside down from the mast's rigging, as they pull the man up the safety harness around the stuntman's ankle is visible.
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.