Because you wanted Deeks to feel like an “other” when he appeared, you didn’t prep for the film alongside Nat Wolff and Adam Long. Were they aware of what was happening?

[Laughs] I think they felt that I was trying to seduce them.

What disturbed you most about the documentary?

It raised a lot of questions — and a lot of questions about myself. How would I react in a situation like that? Do I have the moral courage to say when enough is enough or when something is wrong? Whistle-blowers are vital to a democracy, and I’m very troubled by the way they’re being persecuted today. Having served in the military, I’m not naïve and understand that there are things that you don’t want to go public. But when there are wrongdoings, there’s got to be a channel to address that, and they’re referred to today almost as if they’re spies. We would not have had Watergate without Deep Throat. We would not have had the Pentagon Papers without [Daniel] Ellsberg. It’s important to have people in authority be held accountable. Because if they can act with impunity, then what kind of society are we creating?

Drawing on your own military experience in Sweden, how do you explain the dynamic between commanding officers and enlisted men that makes soldiers do things they wouldn’t ordinarily consider?

You’re fascinated by them. When I first joined, I remember a week or two when we’re on base and the guys that had been in for a year already were out on a mission. We were sitting there in our crisp, brand-new uniforms, nice polished shoes, and we hadn’t yet earned the hat and the symbol on your shoulder and the dagger that our unit had. And when they came back after two weeks in the woods with the smell and bloody knuckles and dirt and a uniform that’s been out in the field for a year and the hats, and the daggers on their shoulders, I remember looking at those guys like they were the coolest human beings on the planet. If they ever said hi or something, we’d just melt.

Let’s talk about that other sociopath, Perry in “Big Little Lies.” Your character was already dead in Season 2, but you frequently showed up in flashbacks. Did you film new scenes?