See the first clip about the mistake, yeah Justin handled it pretty well actually.
The Second clip, Justin's just being a dick. See to some people saying something like the interviewer said about a guy in the band One Direction liking older women, that would actually be funny; you laugh and reply something like, no my mom wouldn't do that, but to say something like "i'd worry about your mom bro". One, thats the douchebag jock response immature college kids give you, two, since where the fuck does Justin get off saying One Direction are "cool kids" hes roughly the same age as them and the fact that he tries to put himself as better is totally arrogant. Bieber = Immature ,this is why i don't like him, doesn't matter how many millions you have when you can't be a down to earth personality that people will respect.