I think they were all actors, and I don't at all feel like a jerk for thinking it. It's television. That means it's almost certainly 100% fake. Look at all the different camera-shots, the lighting. I call bullshit on the whole thing.It was incredibly didactic and it played straight into the audience's desire to believe that good people are out there with the skill and the energy to lead us forward into racial harmony. Ah, well! It was a nice Sunday-school lesson in how to step up and speak out for what's right... if you believe.
In real life, most people, even good people, think it's best to deploy cold silence as the social pressure against strangers who say things that aren't very nice. But you can't make a TV show out of assorted dirty looks, however sharp and well-aimed.