These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Nightmare Fuel: The squad jumps off of a small cliff to escape the Taliban. When they're rolling down the hill below, there are lots of wince-inducing shots showing them landing in ways that could easily break bones or hitting obstacles very hard, and the whole ordeal leaves them significantly bloodier than the preceding gunfight.
The log where a man is beheaded at the start of the movie still has dried blood on it when Luttrel is dragged over to it.
Values Dissonance: Luttrel is a very conservative Christian from the American South, and has effectively no common ground with the also very conservative Muslim Pashtun. Still, he admires their courage and commitment to their idea of honor, and when describes the the Pashtun attitude towards women, and admits that while their extreme views "may not work for downtown Dallas," it seemed to work well enough for them.
What an Idiot: Averted in that the film takes great pains during the captive scene to let the audience know how hard the team's decision is, effectively silencing armchair critics who might have a Why Don't You Just Shoot Him? approach. Granted, letting them go still wasn't the right move (obviously), but their choices were extremely limited: their operation was already compromised, their radios weren't working properly, and with comparatively innocent actions (such as taking a gun from an enemy) were being severely punished, coupled with a liberal media condemning most military actions as war crimes, they were reluctant to simply kill the shepherds. Doesn't stop most people from coming up with their own solutions (at the very least, zip-tying the boy to a goat or zip-tying them together would have barred him from his Le Parkour and slowed them down, buying much-needed time), but the pressure is very evident in the scene.
While tying the herders up was an option they discussed, they also acknowledged that it got pretty cold in the mountains and there was a real chance they could freeze to death, which would have been treated about the same as if they had just outright executed them.