In other words, his liberal-hippie parents brainwashed him for years about the noble savage and our complicity in his oppression, but now he's met the underdog personally and he's realized his parents set him up for a really bad fall for their own political ends.
Hey, Lady! You hit the nail on the head.
Probably exactly what happened. He may not have been little Johnny Jihad, just some skull-full-of-mush moron from a hippy-dippy family who thought he could pull a Timothy Leary and "Turn on, tune in, drop out" from the Army and do a walkabout in Afghanistan. The Taliban probably couldn't believe their luck when they came upon him looking for some poppys, and grabbed the idiot.