Continuity mistake: After Judy is shot by the poison flower, Peter cradles her in his arms. That is in close-up. When it goes to wide shot, he isn't cradling her anymore.
Factual error: Carl tells Alan that his police cruiser is brand new, but the Chevrolet Caprice he is driving is a 1991 or 1992 model as it has "skirted" rear wheel wells.
Continuity mistake: When Judy is fighting off the spiders, the floor breaks and a purple plant comes out of the floor and shoots her in the neck. You can see the barbs, but in the next shot when her brother starts running toward her, they magically disappear, and in the next shot they appear again. (01:30:30)
Continuity mistake: In the scene in which an ambulance wrecks the back of Judy and Peter's realtor, the license plate on the front of their car reads DBA-454. However, in the scene where Carl finds his car wrecked into a tree, when he backs out, his license plate also reads DBA-454. (00:38:50 - 00:52:35)Obvious