Yep. They might be enemies within. Head on a swivel, guys!

My favorite is, "stood like a sentry at the front door". So he stood in a clearly visible area with his rifle upright next to him? He's a Marine, he knows what these words mean. Or he's supposed to at any rate. Maybe he meant he was standing there with a holstered pistol, waiting for visitors to present ID? Did he make sure to change into the uniform of the day and write himself up for two imaginary uniform faults?

If this wasn't a national election I'd be laughing and have ten more jokes about his "combat" experience. It's not everyday the Army gets to dunk on the Marines. Not with most civilians convinced every Marine is better trained than Army Rangers.

Like a lizard dropping its tail to distract the attacker.