What exactly does the Lakers first half performance prove?

Is the Lakers' dominant first half performance proof they are a talented, championship caliber team? Or is it an indication of their capability to underachieve and play down to their opponent? It's plainly obvious the Lakers are the better team. I don't want to count the Lakers out, because they played one poor series. The Celtics struggled last year before they found their stride. However, the Lakers don't have the same defensive focus as the '08 Celtics. They can't just turn it on at a moments notice and hope to win a title.