You're conveniently ignoring game's 3 and 4 where the defensive philosophy change came about. In game 3, Parker had 5 TO's, shot 6/12 and had a -13. I remember it being Thabo's guarding him that took him out of the game. In game 4, Parker shot 5/15 and played a little better with regard to turning the ball over. Nonetheless, Thabo still disrupted his ability to get the Spurs into comfortable sets. In game 5, Parker scored 20 points but 10 of those were on free throws (some of those calls were just blasphemous btw), he shot 36% on 5/14 shooting. I think Thabo had a lot to do with the subpar shooting. Game 6 is the only game I think Parker wasn't affected as much by Thabo. Parker was VERY aggressive in that game early on irrc.
The point I'm trying to make is Thabo had a lot more to do with the outcome of this series than you are willing to give him credit for.