So one of those girls are a daughter of a co-worker of my wife's.
Apparently it's not so cut and dry. The girls were dared by another classmate to send him a video of them shouting "surgeon cuff". The video then got reversed and posted to Instagram.
It's still a shitty situation all around and who knows if the girls clued into what they were doing when they filmed it.
I don't think you realize how sound works.