I'll Fix It - S4-E2
Continuity mistake: When Station 51 is at the scene of the oil well eruption, underneath a house which was built atop an abandoned oil field, just after Johnny tells Roy that he thinks the whole foundation is slipping, it cuts to a shot of the front porch as one of the porch columns (and part of another) breaks and falls. However, when the guys finally free the trapped man and carry him out, all the columns are upright once again.
I'll Fix It - S4-E2
Continuity mistake: While Roy and Johnny are under the house with the oil eruption trying to free the trapped man, they get covered in black oil and mud even though they're wearing turnout coats. It drips down their necks and their pants are soaked with it. When they get to Rampart with the victim, Roy says that he and John should get washed up, but when they talk to Dixie they haven't just washed up, their clothes are now impossibly spotless.
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.