Question about credits in music videos and commercials

Should all credits for commercials and music videos be uncredited, unless a person/band is actually given credit onscreen? For example, this beer commercial currently lists everyone as being credited, but obviously nobody in the commercial (watch here) is credited onscreen. Should everyone be uncredited, including Brad Pitt and David Fincher? I don't know if there are any commercials that have any onscreen credits, but I know music videos sometimes have onscreen credits. Is a band/artist technically uncredited for their own music video (unless, of course, they're credited)? I'm confused about this.