The Associated Press, who called the election this year, and who has been calling US elections since 1848, didn't call the election for either side in 2000:

"AP did not call the closely contested race in 2000 between George W. Bush and Al Gore – we stood behind our assessment that the margin in Florida made it too close to call."

https://www.ap.org/en-us/topics/politics/elections/how-we-ca...