The Spurs are a flawed team. They fell into the trap, if it is a trap, that the Lakers fell into of going with seasoned vets to milk the years they had Duncan in his prime. They passed on developing young talent. They got caught in a money bind of needing to resign Ginobili and Parker so they had to let go of players like Jackson, Hedo. They had a faisco in the attempt to sign Kidd where they could have kept Claxton solving for the long term their backup PG issue. They also were interested in Howard that year and drafted just before Dallas but because they were trying to save cap space for Kidd and a center they basically traded away the pick selecting Barbosa for the Suns in exchange for a future pick instead of picking Howard. Boy was that dumb. Spurs had to dump a couple of picks to get rid of Rose. Last year they had a trade worked out with Denver to pick Jameer Nelson but Orlando grabbed them just before that. They also had Krstic targeted but signaled their nterest and Thorn grabbed him just because they knew SA wanted him. They overpaid for Rasho who has very limited flexibility in matchups. So basically bad planning, bad luck.
But don't write the Spurs off yet. In a way it's good the Spurs get bounced if they do. They'll be forced to address their shortcomings. They showed they know what they need to do by trying to trade Barry for JR Smith which almost worked but the Atlanta GM was at a funeral and the three way fell through at the deadline. Spurs do have some pieces in place, Ducan who is showing in this series he is stil MVP Duncan, a young and improving PG and Manu who has been hobbled all year by injuries.
Spurs also have some other pieces coming. Scola who many consider the best big man in Europe, certainly the most skilled post player to add or use in a trade, Javtokas who some consider the best defensive big man in Europe, last year's pick Mahinmi who may be the long term big man solution and a kid Sanikidze who some considered the sleeper of the '04 draft who ahd some leg injuries, has been rehabbing and will play on the Spurs summer league team. So all is not bleak in SA.
In terms of this series I think Pop has shown his genius keeping the Spurs in a series where they have deep flaws and don't match up well with Dallas. In fact my bias is that given equally good or bad reffing in this series SA would be up 3-1 but I don't expect everyone would agree with that for various reasons.
In term of Sac beating the Spurs, there were some matchup problems for the Spurs but not enough for the Kings to overcome the problems that SA posed for them.
But it ain't over yet in SA (whistling in the dark)