Oh puhleeze! Because Berryman, whatever that is, said so? Everyone acknowledges the AP poll and you know it. There have , traditionally, been 2 major polls and, occasionally, they split. When they split, both teams are recognized. Every press account under the sun has referred to them as back-to-back national champs. The fact that you don't like what is commonly acknowledged by every major paper doesn't mean it isn't true.
The AP WAS was the poll before the implemtation of the BCS. If the 2003 situation had occurred before the PAC-10 and Rose Bowl joined the BCS then you'd have a point.
For example, when USC and Alabama split the AP and UPI in 1978 or 1979, both teams had a valid case to consider themselves national champions. The same with Washington/Miami, Ga Tech/Colarado and Penn State/Nebraska. Those were all pre-BCS.
At that time was just a component of the BCS just like the Sagarin poll and several others.
Look, if Div-1 developed a full fledged playoff system, would you consider the AP poll winner the champion or other winner of the playoff? The BCS certainly isn't perfect but it is the playoff system that everyone, including USC and Auburn, agreed to.