Revealing mistake: After Rachel tumbles down the well, we see her heavy-duty Eveready Commander Flashlight, 12-volt battery and all, bobbing above the surface of the water like a cork. Which is ridiculous. A real 12-volt Commander Flashlight would sink like a rock, because it weighs about 4 pounds. However, the filmmakers needed to explain how Rachel could see at the bottom of a pitch-black well, so they used a lightweight, floating flashlight prop, supposedly providing a light source for the scene.
Visible crew/equipment: When Noah and Rachel get back home to Aiden and Noah picks him up you can see a crew member's silhouette in front of a window. (01:36:44)
Revealing mistake: When Rachel searches online for "Moesko Island," you can see in the address bar of the browser that she is really looking at local files (C:\WIN98\Desktop\search.com\... etc). (00:42:30)
Continuity mistake: When Aidan and Noah are talking in the car, outside of Katie's house, Aidan is coloring on a blue lap tray. When Rachael comes to get him out of the car a couple of minutes later the lap tray is now green. (00:51:25 - 00:53:10)