Contact was lost on Deacon and Chris between Barstow and Baker, CA. The only through road between those cities is Interstate 15. There aren't any back roads for them to have taken.
Wouldn't the SUV of a SWAT officer providing first-rate private security have a GPS, or better, tracking system so the team and company could have tracked where they were when the trouble started? Even if its device was disabled in the rollover, they still should have access to the last operative location.
Dubious tactical decisions for SWAT officers: Why didn't they take the truck of the dead sicarios and get out of Dodge? When they chose to defend from the town, why didn't they take the grenades and other weapons from the first pair to use on the next wave?