Other mistake: In the scene where Mikey, Brand and Mouth are listing the exaggerations Chunk has come up with, Mouth says "And I bet it was even more amazing than the time you ate your weight in Godfather's Pizza." When he gets to the "Godfather's Pizza" bit, it becomes clear that this has been dubbed over the original filmed scene, as his mouth does not match his words in the slightest.
Visible crew/equipment: In the shot of Mama Fratelli waiting outside for Jake in the ORV, you can see the reflection of some film equipment in the small triangle window next to her. (00:01:30)
Continuity mistake: In the beginning scene of the cop calling out the inmates for their lunch, just as he calls "Hey Turkey." you can see the shadow of the supposedly hanged Jake Fratelli on the right wall. The shadow is totally inconsistent with the design of the cell and position Jake was hanging in. (00:00:45)
Continuity mistake: In the scene where the kids are crossing the wooden bridge near the waterfall, Data is seen holding a lantern. After he does his "slick shoes" routine, the lantern has disappeared.
Continuity mistake: In the scene where they are playing the bone-organ to escape, the Fratellis walk across the beam then climb the rocks to get to the room where the Goonies are. In one of the rocks there is a tall metal post sticking up. A shot shows one Fratelli brother stick his hand on this post to pull himself up, but in the next shot the hand is gone and a moment later the Fratellis emerge from the water.
Continuity mistake: When you first see Andy's hands being tied, you can see that they are tied fairly tight. Right before she goes off the plank, you'll see that the rope is barely around one wrist. In the next shot as she is going into the water, you can see her holding her elbows with both her hands. Then when Brand rescues her the rope is secure again. (01:32:40)
Continuity mistake: When the Fratellis leave the County Jail, the first police cruiser which makes the U-turn has a smooth chrome bumper with only a recessed license plate at the center, but when they make the first left turn, that squad car now has a chrome bumper with driving lights at each end and bumper guards on both sides of the license plate. It's funny how when they make the next right turn, the car style actually changes mid-turn, between shots - just before the second police cruiser joins the pursuit. (00:02:25)
Continuity mistake: When the back of the Fratelli's ORV is riddled with bullet holes, you can see they make a distinctive backwards "L" shape above the Jeep letters. Later, when Chunk examines the ORV, the bullets holes are now in different places than they were before. Also, the license plate that is seen on the ORV when it is hit by the bullets, changes design as well. (00:02:45 - 00:30:30)