Actually, no conspiracy or slip-up on Timmy's part. President Clinton should and always will be referred to as "President Clinton". All ex-Presidents (and Congresscritters too, I believe) are referred to by their title whether they are in office or not. Tradition and/or protocol dictates.
A) Timmy was talking about President BUSH when he said "President Clinton", and
B) President Bush has been called MR Bush ever since he got elected. Journalism style books apparently changed just about January 20 2001by coincidence.