Continuity mistake: When the Jeep stops in Priceton, we can see its on a single land road. However once it starts to accelerate in the next shot to ram the tree at the intersection, it is now a forked road.
Suggested correction: The road is a standard two way road that is unpainted with road markings. Almost all non major roadways are unpainted and many of them fork into two separate roads.
Continuity mistake: After the private starts shooting and the group Mark Wahlberg is in breaks into smaller groups and starts running in the field ahead of the wind, his group consisted of himself, his wife, the little girl, Jess, and two women. One woman was heavyset wearing blue with dark hair. The other was thin with red hair. The next scene of them running ahead of the wind, their group now has two boys, one black, Jerry (I think), one white, Josh (I think), instead of the two women. (00:48:28)
Continuity mistake: In the very first scene where Elliot comes home and finds Anna sitting on the couch we see that the handbag she has is black but a couple of minutes later it's changed to yellow.
Continuity mistake: When the woman shows the video at the Filbert restaurant of the man being mutilated by the lions, the position of her hand holding the iPod changes between the front and back shots. (00:24:25)
Continuity mistake: When the train first leaves Philly heading to Harrisburg, there are 4 cars pulling out and 5 on the overhead shot. Also when pulling out of Philly it is a diesel engine and the overhead is electric.