I wondered this too so I went back and watched again. It appears it was him filming he got a shot of his forearm tats in the video and could be heard yelling stop it to the kids. Also said he was with his wife when she was attacked.As for the guy whose wife got assaulted, I wasn't there. I didn't personally see him stand by while his wife was being beaten; maybe he did, maybe he didn't...I don't know for sure.
The gated community thing is just a guess on my part though as evidenced by the gates across the road in the background.