Continuity mistake: When Joe arrives at the old house, both his hands are on the gate. Then when you see Joe again from the sidewalk, his left hand is not touching the gate anymore. (01:05:30)
Continuity mistake: When Joe Dirt and the indian are in the desert and they are playing with the roman candles, Joe Dirt trips on the A-Bomb and the candle stick flies out of his hand. But in the next scene, when he wakes up the candle stick is in his hand again.
Other mistake: When the old man gets his foot caught in the railroad switch, the switch closes on his foot, trapping him. As the camera pans out we see that this was not an electric switch but a hand throw switch, meaning that someone had to be standing at the switch manually operating it to close on the old guy's foot.
Character mistake: Joe Dirt mistakenly refers to his 1967 Plymouth GTX as a Road Runner while talking to Jill at the carnival.
Continuity mistake: During Buffalo Bob's first appearance, he's holding a rake with both hands. In the next shot, he's holding it with just one hand.
Answer: It's not so much a joke with a punchline, but more like a funny phrase. He was affiliated with the mob, and as such, has most likely been in violent situations. He asks "does your mother sew" and then punches his refelection in the fire extinguisher case (someone's face if a fight was really happening). The "get her to sew that" comment implies that the person he hit would have needed stitches. (thus the reference to sewing.)
Jazetopher
He was referring to fixing the hole left in the clothes after being shot.