Tell big boss, or no?

My best friend was called a “nigger” repeatedly by one of her managers as a “joke.” I’m planning on emailing their big boss (owner of the restaurant) and letting him know how I’m upset at this. 2 days after she was called the n word, they had a meeting. One of the other managers said, and I quote, “If you have a problem with your coworkers, and it doesn’t involve the restaurant, do not let me know.”

When she told me this I was LIVID. We live on an island where majority of those who are from stateside are military/tourists. Obviously they are looked at different.

I hate the fact that almost everyone working in that restaurant knows what he did, but no one is acknowledging it. It is obvious racism.

So do I email big boss, or no?