Factual error: If the lake was already acid while the family was in the lodge for a while, the wooden docks should have already been dissolved.
Suggested correction: Different materials react with sulphur dioxide in different ways. Sulphur dioxide (or SO2) wouldn't actually dissolve wood, it would just char it and weaken it.
Other mistake: When the lahar slams into the bridge, it seems strange that none of Paul's windows shatter while he's trying to get across. A lot of mud and debris slams into all three vehicles, but their windshields and windows remain intact. Also, the bridge entrance is washed away, but the rest of the bridge remains standing, until it tilts upward and disappears, taking Paul and his van with it.
Continuity mistake: After Terry falls in the crater, watch Harry climbing down to him. Harry is almost down, then the scene flashes to him at the top of the rim again, and he makes his way down a second time.
Revealing mistake: When Lauren screams after seeing the bodies in the hot spring, someone grabs her, but it is none of the characters in the scene.
Character mistake: When Harry is registering, he has glasses hanging around his neck and is wearing another pair, presumably readers, while he checks in. After exchanging pleasantries with the proprietor, he takes off the glasses, puts them on the counter, and leaves without them. (00:08:05)
