I can't speak for whether that was true in the past. (If you really care i can bug people for historical data) However, as of 2014 average interview score was

I can't speak for whether that was true in the past. (If you really care i can bug people for historical data) However, as of 2014 average interview score was very well correlated with job performance (I can't give you further exact details because they are still marked confidential and i can't find a paper or anything that has disclosed it). Note very clearly the word average above ;) Individual interview scores are definitely not predictive of job performance.