Other mistake: Another note about Clark's falling through the ceiling and onto his son's bed: Take note of the shot of him in the attic after falling through the ceiling. He's standing on the upper bunk of the bed now, but from the shot in the attic, he's only down to his knees or so. Assuming his home's ceiling joists are 8 inches or so, then the mattress of the upper bunk would have to be no more than, say, 10 inches from the ceiling for that much of him to still be in the attic while standing on the bed. I've never seen a bunk bed whose upper bed gave you less than a foot of space between mattress and ceiling! (00:33:05)
Other mistake: When Clarke and Eddy are drinking eggnog by the tree, and Snots is drinking the tree water, look at the tree's trunk. It's a birch tree not a pine.