The green patch on the snowboarder's trousers (in the forest at the beginning of the movie) switches from the left to the right leg and back again multiple times between shots.
The blood on the hood of the truck appears and disappears. When Jim and Barry find the truck, there is no blood; when the camera pans across the damage to the vehicle it is there, then is missing again when Barry tries to open the hood.
Near the end of the film a massive avalanche engulfs the beast as it approaches the father and daughter. They shelter behind a tree trunk which somehow protects them from the avalanche but when they emerge afterwards the adjacent trees and shrubs appear completely unaffected.
At 45:04 Rob blunders into discovering the Snow Beast's lair by falling through the snow at the top of it's cave. The edge of a white board can be seen to the right of the screen as Rob and snow fall to the bottom of the cave. Looking up at Jim from the floor of the cave the hole is square with edges of the trap door visible.
In several scenes, when the Snowbeast turned its back toward the camera, the back of the creature suit is clearly open, revealing a black body suit underneath.