I am guessing someone who works at the station shared some internal documents.
I remember in the mid 90s watching Nickelodeon before school and they played an entire 30m block of commercials instead of a program. They probably lost the tape or something.
There are definitely outside organizations whose sole responsibility is to monitor TV/radio broadcasts and nowadays even podcast sponsor breaks to ensure that ad copy is inserted as agreed. (Source: I was contracted to do some of that work for a time.)
I remember in the mid 90s watching Nickelodeon before school and they played an entire 30m block of commercials instead of a program. They probably lost the tape or something.