In one of the opening scenes, when Kelly drives away from her apartment she is wearing large, golden hoop earrings. When we see her in the car she is wearing multi-colored teardrop earrings, and when she arrives at the family cabin and disembarks from the car the golden hoops are back.
After the twins' car crash, one of them has a wound on her thigh that's bleeding profusely like a running faucet to the rhythm of her heartbeat. Telltale sign of a ruptured femoral artery and at that rate of blood loss she'd be dead within 2-7 minutes. Especially since her twin removed the strap she had tied around her leg to stave off bleeding.
When Janna and Fiona run out of the Cabin we see Callie grab a shotgun and begin to run after them. While Callie chases them you can see the camera mans shadow running along side of her as she runs down the trail.