Factual error: When the shop vac shoots the golf ball at Mr. Wilson's gonads, it only affects him for around ten minutes. The shop vac was able to shoot a glob of paint over 50 feet in the air so the speed and impact of the golf ball would have done much more than put Mr. Wilson in extreme pain for a short while. The impact would have likely caused internal bleeding, swelling, causing him to vomit, probably a rupture, requiring him to be hospitalized. There is no way he is walking away from that, he wouldn't even be walking at all.
Continuity mistake: When Dennis is in Mr. WIlson's bathroom after his bath, pouring mouthwash in his nose spray, Dennis has toothpaste all over his chin and mouth. When they show Dennis from the side, it is gone. From the front it is there again. This happens several times in the shot.
Continuity mistake: When Dennis is in the bathtub you see some toys floating around in the tub. When it cuts from above him the toys are gone. Instead the whole tub is covered with foam. (01:28:20)
Revealing mistake: In the scene where Mr.Wilson slips on the bath water and falls, after he does the split you can see his right leg is fake.
Continuity mistake: When Joey is dragging the perambulator you see him dragging it while walking backwards. When it cuts he is dragging it behind him walking forward. (00:20:00)
Continuity mistake: While Dennis is stoking Switchblade Sam's campfire, he flings an ember that falls down the back of Sam's pants. The smoke (and later the flame) are coming from the center seam, yet after Sam puts the fire out the hole is a couple of inches to the right.
Revealing mistake: One of the first shots of Switchblade Sam is a closeup of his face, in which the viewer can see he is wearing contact lenses. No way this homeless-type villian with blackened and missing teeth, old torn clothes and unwashed stringy hair maintains contact lenses. (00:18:20)
Continuity mistake: When Dennis pinches Mr. Wilson when Mr. Wilson is pretending to be sick, you can see Dennis pinch but he doesn't use his index finger. When it cuts he is using his index finger. (00:04:05)
Continuity mistake: In the scene where Dennis and his mother are on their way to Margaret's house, the lock on the passenger's side door is locked and then unlocked when the camera view changes. (00:11:40)
Continuity mistake: When Switchblade Sam is in the water and Dennis lowers him the rope, he barely gets it around his ankle. When he gets back onto the bank, it has somehow become neatly tied around his waist (obviously for the stunt that follows).
Factual error: When Dennis uses the shop vac to clean up the paint he spilled, he takes the vacuum outside and flips the switch to "out" which the shop vac shoots a glob of paint into the air. In reality, the paint would actually ruin the fan inside the shop vac, causing it to jam.
Other mistake: When Dennis is in the woods right before he bumps into Switchblade Sam, he passes an owl that hoots but the movement of it's throat aren't at all in conjunction with the noise.
Factual error: When Dennis's mom is outside Margaret's house and she is dragging Dennis inside, take a close look down the street. You can see Mr. Wilson's house and Dennis's house right next to Margaret's house. How is that possible if they drove to get there? (00:17:00)
Audio problem: When Dennis shoots a marble at the robber's head, when the robber goes to wash his head in the water, you hear Dennis talking, but he is not moving or moving his lips in the background.
Continuity mistake: When Dennis climbs onto Mr. Wilson, who is pretending to be asleep, his left shoe is untied, but when he leaves and runs home it's tied again.
Continuity mistake: During the bathroom scene, Dennis pulls the cap off the nasal spray bottle and throws it. When the scene cuts to him holding the mouthwash, the bottle is sitting with its cap on, and immediately after the cap is off again.
Continuity mistake: In the bedroom scene, Dennis' overall buckle is normal. But after he pops the cap off the aspirin bottle, it's pushed all the way to the side. The next shot shows it as normal again.
Plot hole: During the bedroom scene, when Dennis shoves a flashlight into Mr. Wilson's mouth and nose, Wilson opens his eyes. It would be impossible for Dennis not to notice his open eyes, and realise he's faking being asleep, especially when he puts the light into Wilson's nose.
Plot hole: Towards the end of the movie we see Mr. Wilson peek out from his front porch, surprised to see Dennis biking back home with his wagon carrying Switchblade Sam, tied-up and partly unconscious. Either Dennis must have some hidden super-strength or knew how to tweak the laws of physics there is no way that an eight-year-old kid of his build could carry an adult of that size to his wagon let alone easily bike home with Switchblade Sam's weight. Plus being an experienced criminal like Switchblade Sam he may have offered some resistance in being caught doing so much less submit to a mere kid. (01:50:00)
Chosen answer: He doesn't hate Dennis and does not want anything to happen to him. He's just a rather crotchety old man who is annoyed by a precocious kid. He may not expect Dennis to listen to him, but he at least makes the effort to reach out as most adults would.
raywest ★