When Mark rescues Demetri from death, "The End" date written on the blackboard is December 12th 2012. However, when he's explaining later for his colleagues, It changes to December 12th, 2016.
Frost directs Mark to take HWY 57 into the Antelope Valley and then walk towards the Tehachapi Mountains. The HWY that goes into the Antelope Valley leading towards Tehachapi is actually CA State HWY 58.
Mark arrives to rescue Demetri and assesses the rig with his gun inside. He has access to the trigger and external hammer. He could easily have prevented the gun from firing by inserting a solid object behind the trigger or in front of the hammer, but he did neither.
The escape from the LA County jail could not have taken place as depicted. The LA County jail does not utilize window washers. Since it is a secure area and the person in custody was a high value asset, no one could bring explosives in as was shown. Additionally, the armed guards were at the window within seconds, so the escapee was still within handgun range.
While Frost is guiding Benford out to the desert, Frost gives him the direction "turn right". Mark then turns left.