Continuity mistake: They travel without their helmets but when they are about to go underwater they magically appear.
Continuity mistake: The orange Peli case with the flare gun reappears back on top of the cupboard. This is after Norah has put the case in front of her on the table and is looking at it at the same time. (01:07:00 - 01:07:24)
Continuity mistake: In the opening shot as Norah is brushing her teeth, in one shot she pulls the toothbrush out of her mouth, the next shot the toothbrush is in her left hand as she grabs a paper towel, the next shot you see both empty hands as she uses the paper towel to scoop up a spider, then the next shot has the toothbrush back in her mouth without a transition of her putting it back in her mouth. Then as she puts the spider down outside of the sync, the toothbrush switches sides of her mouth immediately in the next two shots.
Answer: The helmet is designed to withstand immense pressure that is equally distributed over its entire surface. Direct blunt-force impacts by a hard metal object like a fire extinguisher may compromise the structural integrity.
raywest ★