News media usually prepares announcements for either candidate to win. Sometimes they become so sure that one candidate is going to win, that they don't prepare much for the other candidate. This doesn't mean they "know" who's going to win. It just means they think they know.

See: Dewey Defeats Truman

Those look like test numbers. They probably input numbers in and a system calculates percentages. They're probably just testing the system and accidentally revealed it.

The thing that really makes me doubt the conspiracy the most (in this particular story) is that it's a minor affiliate station: WRCB out of Chattanooga. If there was some vast conspiracy involved here, it wouldn't be very wise to let every single affiliate station in on the information. Even if just essential people at each of those stations, you would still have hundreds if not thousands aware of the situation. That information would be leaked. There would be no way to keep that many people quiet.