Flamed out? Did you even watch the series? It went 7 games against the only team that could matchup with them in the entire league (OKC), and arguably the closest series of the year. Grizzlies would've won the championship last year the way they were playing defensively and with that inside game, if they were on the opposite bracket of the Thunder or had Rudy Gay. Can you imagine Dirk trying to defend Marc Gasol and/or Zach Randolph? Dominating the Heat is easy when all you have to do is sit under the basket on defense and guard the likes of Joel Anthony for half of your minutes.
Basketball is all about matchups. At the end of the day, if you run into a hot team or a team that matches up well against you, you're going to either get beat or barely win. The Grizzlies were a better team compared to the Spurs. The Thunder were better than the Grizzlies, because they had three great defensive big men, and had obvious advantages at the wing and point guard spots. We were better than the Thunder because we were able to expose their lack of scoring options inside and we had great spacing/shooting.
If we had gotten 4 straight great matchups, like the Mavs did, we would've won a championship last year. We would've absolutely soul crushed the Mavericks in a playoff series, just like we did in 2010. Anyone would've crushed the Lakers last year, with the exception of the one team they beat, the Hornets (who miraculously won 2 games, and Chris Paul looked like a superstar again after playing terribly, for his standards, the entire regular season), and the Blazers.
We couldn't beat the Grizzlies. That was it. And we happened to run into them. happens.