It didn’t happen in the Super Bowl; at least not from the Cable Company. Those have always been on broadcast channels and we never inserted on a Broadcast Network.
It was likely inserted at the local TV station.
The commercials were triggered by a “silent” tone that started a local set of commercials. Way back in the day they used a bank of industrial VCRs to insert the ads. It was fun to watch TV and see one of the VCRs die…and send out garbled junk for 2 1/2 minutes.
So was it legal for the local station to do that?