Thunder players aren’t the only ones picking up lessons in their first-round series against the Los Angeles Lakers. Maybe coach Scott Brooks learned a thing or two as well. It is, remember, his first go-round as the head man during the playoffs. And Brooks made a critical miscalculation late in Sunday’s 87-79 loss to L.A. He stuck to his guns. The coach continued to do what got his team here. Ordinarily, that is sound strategy. In the playoffs, it could spell disaster. And while there was plenty to point to for Oklahoma City staring at a 1-0 deficit in this best-of-7 series, one decision by Brooks could be considered just as costly as anything else. With 1:48 left to play in the third quarter, Brooks replaced Russell Westbrook with Eric Maynor. It was the same roundabout time on the first- and third-quarter clock that Brooks always gives Westbrook a breather. But, at that point, the second-year point guard was bringing the Thunder back and keeping his team in it. Westbrook sat roughly 40 seconds after finding Serge Ibaka under the rim for an uncontested layup. Westbrook scored or assisted on 24 of the Thunder’s last points. Westbrook sat with the Lakers ahead by nine. The Thunder pulled within six with 5.8 seconds remaining. OKC would have had the momentum had Kevin Durant not almost tackled Lamar Odom in the closing seconds of the third quarter and given the Laker forward a free trip to the line to push the lead back to eight entering the fourth quarter. Brooks didn’t reinsert Westbrook until 8:35 was left in the fourth. The coach started the decisive fourth quarter against the defending champions, on their home court, with one starter (Jeff Green) three reserve rookies (Maynor, James Harden and Serge Ibaka) and one role player (Nick Collison). Again, it’s what Brooks has done all season. But this isn’t the regular season. This is the win-or-go-home portion of the year. And this isn’t the Minnesota Timberwolves. These are the tall and talented Lakers. And against L.A.’s defense, albeit primarily the second unit of Jordan Farmar, Shannon Brown, Luke Walton, Lamar Odom and Bynum, the Thunder’s lineup laid an egg. That eight-point lead quickly stretched to 11. The Thunder became out of sync on offense and lax on defense. Oklahoma City scored on just two of its first five possessions in the fourth and had two turnovers. The biggest giveaway being a shot-clock violation in which Harden had no clue of the situation and passed off to Green with one second on the shot clock. Brooks then summoned Westbrook and Durant off the bench. But it was too late. Westbrook had lost his rhythm, and the Thunder had long lost its momentum. We’ll see on Tuesday night if the coach learned as much as his players.