Can't figure it out

OK, so you're watching the Heat and the Nets, and at one point in the fourth quarter you're thinking, 'There's no way the Heat can lose this game.' It's the same thought you had when you watched the Heat play the Hawks at home.
And then, somehow, the Heat loses, and it's hard to explain what you just saw.
There are a handful of games where the problems are obvious, but in games like this one you just have to really study the stat sheet to believe what you just saw, because it seems improbable for these guys.
It's like Udonis said after the game, "I've seen bad teams before, and we're not a bad team."
The Heat shot 47 percent, shot 29 free throws, got 41 from Dwyane and played what appeared to be active defense against the Nets. And yet, when you look at the stat sheet, you see the Nets lived at the foul line even more than Miami, outrebounded Miami by eight and outscored the Heat in the paint by 10. Those are the signs of a team that doesn't play nearly enough defense. Even with that, the Heat was one desperate Vince Carter three-point miss away from winning in regulation. Instead, the shot goes in and Miami loses in overtime.
You can't blame Alonzo's absence for this loss because it was happening way too often even when he was available.
Not sure what the answer is, but there are still even more questions from a coaching standpoint. I can't for the life of me figure out why Riles continues to start Ricky Davis in the second halves. Dorell had seven first-half rebounds and was playing great help defense as well as creating a couple of easy buckets. And that was with the starters. Then he doesn't start the second half and the chemistry is entirely different. Riley is not exactly a guy who succumbs to players' egos, so it shouldn't be a matter of him simply appeasing Ricky. I think it's just a coach grasping at straws, and it just doesn't make any sense. This team needs continuity, and changing starters each half doesn't support that.
Then there's the inability to adjust within games in offensive play-calling, whether it's against an aggressive defense that's trying to keep the ball out of Dwyane's hands or against a simple zone defense, which continues to baffle this team. It's mind-boggling for a coach that is normally a lot better at figuring these things out.
Still, this game was lost on the defense end, and it might just be a matter of guys moving better defensively for longer periods of time, or adjusting how the team plays pick-and-rolls defensively. Something's got to give, because otherwise there is no reason to believe this can change.