they've actually clarified. some of marks friends told bambam that nig*** meant brother which is why he said it in that video. I watched it multiple times and he did clearly say that.
however, I agree with one of my favorite youtubers in the sense that it had become a commonplace word so people use it more casually. however many like it to keep to a double standard - only blacks can say it to others of any race buy not the other way around.
so its not his fault in any way shape or form. however those in the spotlight in Korea are held to a higher standard than in America - part of why they're called idols - they're idolized, meant to be perfect to everyone, etc. it's too much to ask for and that's why with as demanding as people are becoming we're seeing more and more of our favorite artists and idols having to apologize for things that any humans shouldn't really have to - at least not to the extent they're made to.
everyone makes mistakes. but idols aren't allowed to and fans won't let them forget that