The Spurs had beaten the stuffing out of the Lakers in the first game, and then Dice had the tip in on the second. Laker nation was in a frenzy, and everyone knew they were mad and treating that third game like their super bowl. In fact, it was probably the best effort that Lakers team gave the entire season, including the playoffs. The Spurs knew it was just another regular season game against a non-division opponent who they'd beaten twice, so they didn't really show up. As you said, Pop had given them an excuse for not showing up by treating the Lakers like something special. He put them in a losing frame of mind, and then fatally disrupted the team afterward.
Phil Jackson didn't win a le, but he clearly mind ed Popovich into ruining the Spurs last year. Pop was afraid to try for the best record against the Lakers which led to Manu's injury in the Phoenix game.