23,000 New Testament Changes

A recent BBC TV program reported 23,000 changes to the New Testament, based on an examination of the Codex Sinaiticus. David Instone-Brewer said it was misleading for the BBC to suggest these changes were deliberately introduced into the New Testament for theological reasons, rather it was a "desire to record differences in manuscripts so that the original can be preserved". I don't get it! What is Instone-Brewer trying to say? There never was an original of the New Testament.