When the detective watches the video of the crime scene, he says something like "there's Hanna, at 6.04". However, the time stamp on the video is a completely different time. A few seconds later we see the video screen again the the time stamp is correct.
In the Eden Lake, Minnesota's sheriff's office, there is a map posted on the wall which one assumes is supposed to be of Eden Lake. In actuality, the map is of Vancouver, British Columbia, Canada, the metro area of which is where this movie is filmed.