I haven't seen the show, but I would do something. I have intervened about five times in my lifetime.
Twice against my step-father who was fighting with my mom and three was with total strangers. One time he was scuffling with her, and I got in between them and screamed at him to stop. The second time was when they were fighting in the kitchen and he started pointing a large kitchen knife in front of her. So I put out my arms, and yelled at him, "go ahead and cut me". He threw down the knife and left the kitchen.
Then I came upon an accident when I was about 22 between an 18 wheeler and a car under a viaduct in a really bad neighborhood. I stopped my car, ran across the street to the only place around - a liquor store - to use a pay phone and called 911. The people in the place looked at me like I had 3 heads and they could tell I didn't belong in their neighborhood (white girl in a minority neighborhood). I stayed long enough to make the call. I came back to my car, and made sure the guy in the truck was okay (he was bleeding a little on the forehead I think). I think I couldn't leave because he was blocking my car, or maybe I did when I heard the cops coming. I can't remember it was about 20 years ago.
Then later, in college, a social studies teacher got beat up a bit because he was protesting a Nation of Islam (Louis Farrakhan) group meeting and passing out flyers to people leaving the auditorium. I was studying in a nearby room with a friend and heard a commotion. I ran out of the room and there was the guy moaning and his mouth bleeding, a few students looking scared and not knowing what to do, and 3 large men in black tuxedos with their arms folded looking rather PO'd. Naive me knew nothing of what they were, but I saw the man on the floor dazed and incoherent. I don't know what compelled me, but I went to the man and attended to him until the paramedics came. All I did was basically tell someone to get a jacket for under his head, and held his hand and kept him talking and checking to see where he was hurt. I was just trying to keep him conscious because he was really out of it. I only realized later I should have been scared, but I didn't know about the men until later. A few people came up to me and asked me if I was a nurse or something, but of course, I wasn't.
The last thing I did was yell at a woman for beating her child on the legs with a switch at my train stop in Chicago. People were watching, not saying anything, but I went up to her and yelled at her for beating her son. She said it was because he wasn't listening. I told her she needed to stop beating him. If she needed to discipline him, one small spank would have been enough (this was before I had kids and realized spanking was no good anyway). She was all in my face and yelling at me like she was going to do something to me, but I held my ground and yelled at her again. That poor child, he wasn't doing much wrong. He was just acting his age (he must have been about 4 or 5).
I don't know what gets into me to intervene up against strangers. I think it had something to do with being conditioned not to accept abuse by my family. I mean, they tried, but I had lots of practice fighting back. I'm always sticking up for injustices. And, I get an odd sense of feeling alive when I do get to help others like that.