Sam and Dean are both on the floor of Bobby's house and Sam asks: "Did I miss anything?" Dean hits him. Before he hits, his face is all bloody, after he hits Sam and falls back down to the floor his face doesn't have any blood on it.
In the opener, Dean is racing toward Twin Lake to rescue Sam; When the Impala passes the Twin Lake road sign, before the rescue, both Dean and Sam can be seen in the car.
Sam and Dean are in Duluth MN, which is 9.5 hours away from the South Dakota border yet they both manage to get to South Dakota hours before dawn even though Sam arrived at the bar at closing which is around 2:30am. There is no indication that more than a few hours have passed.
When Sam puts his hand on Dean's shoulder you can see Dean grabbing Sam's arm because of the pain. Then the camera switches toward Sam and then back to Dean grabbing Sam's arm again.
Dean's phone still works even after he falls into the water and has spent a few minutes (enough time for Sam to leave and Jo to safely come looking for Dean) in the water.
In the scene at the house that Sam supposedly broke into, Dean flips over the dead guy and you can see him obviously breathing even though he is supposed to be dead.
In order to "erase" the security camera video Dean takes the computer case, throws it on the ground and stomps on the motherboard. This would render the computer itself inoperable but the data on the hard drive would still be recoverable. While Dean may not be super tech savvy (though Sam is and should have said something), he would know enough that it is the hard drive that would need to be destroyed or removed in order to prevent someone from finding the video.