Incorrectly regarded as a mistake: How has Maggie's iPhone battery managed to hold any charge in the 15 years since the blackout? Where did it get enough power to turn on?
The iPhone wasn't running from its battery - it was running from the pendant itself, as were the CD player, computer, etc.
The "sniper rifle" is a bolt action rifle. This action must cycle to load with a manual manipulation of the bolt following each shot. During the shootout, we hear the weapon firing, but never once hear or even see the bolt being worked. Also, as a .308 (judging by the brass), there is seemingly zero recoil.
Monroe challenges Miles about going "AWOL". As a Marine, Monroe should have said "UA" for "unauthorized absence".