(I know little about law & copyrights and such so please feel free to correct any misuse of terms)
By "copyrighted materials", I mean stuff that automatically copyrighted like YouTube videos, as well as things like shots/clips from Disney movies & commercials and such.
By "live broadcast", I mean things like the news, live-streams (YouTube, Twitch, etc.), or anything else broadcasted live to the public.
By "unintentionally shown", I mean the copyrighted materials are shown in the live broadcast without the knowledge/consent of the one doing the broadcast (a pop-up commercial, accidentally opening the wrong video, someone in the background camera-bombing the broadcast, etc.).
Would the ones doing the live broadcast be protected against such unintentional showing of copyrighted materials? What's the worst that can happen?