What happened and who’s to blame for the Miami Heat’s crushing Game 6 defeat?

Depending on what happens Monday night, Derrick White’s last-minute tip-in may go down as one of the wildest, most important shots in NBA history.

to somehow take a one-point lead with three seconds remaining. Butler had summoned whatever magic he had left to score 15 of his 24 points in the fourth quarter, getting to the line 10 times to do so. The final three made calmly from the free-throw line after baiting Al Horford into a shooting foul when he was trapped in the corner.

With just 3.0 on the clock, the Celtics had one last chance to avoid a devastating colapse and save their season. White, the inbounder, looked for Jayson Tatum, who flashed toward the Heat’s center-court logo. Butler and Max Strus bracketed him and successfully denied Boston’s star, who had a game-high 31 points. Marcus Smart ran towards White, caught the ball, turned and heaved an off-balance 3-pointer.

The ball hit the rim, flushed around the right side and popped out on the left side of the basket. White, meanwhile, had left his position on the left sideline to sprint along the baseline. As the ball fell, White leapt and softly tipped it back in.

The buzzer sounded. Butler and Gabe Vincent waived as if White’s tip-in came after time expired. Bam Adebayo walked back to the Heat sideline in disbelief. The officials gave it a quick review and it was clear the basket was good. White, a Boston hero. The Heat, who once held a commanding 3-0 lead in the series, forced to play a Game 7 to make the Finals.

So what happened on that final play? How could the Heat allow White to get such a clean putback? And who — between Strus, Adebayo and the officials — is to blame?

According to coach Erik Spoelstra, the Heat played that final possession to near-perfection. The goal was to deny Tatum the ball, force a tough shot and box out.

“Making that ball go anywhere but Jayson Tatum,” Spoelstra said. “That’s the only place (the ball) could have bounced to hurt us. I thought we had a lot of things covered on that play and sometimes things just don’t break your way.”

Here’s the replay.

Technically, White is Strus’s man, but he was darting back from doubling Tatum, as Spoelstra instructed, and was behind the play. This isn’t an excuse, either. Go to the very beginning of the clip. Strus’s back is to White. His first priority is to deny Tatum. He succeeded. His second priority is to get back to White. He tried. But Smart falls backwards, impeding Strus’s path. The fact that he’s even near White when he tips it in is a credit to his hustle. Freak play.

What about Adebayo? He’s Miami’s lone big man, shouldn’t he be closer to the basket to grab the defensive rebound and end the possession? Not necessarily. Players in these instances are coached to get a body on the nearest body to prevent what happened here — a clean look at the tip-in. With seconds left, the ball falling to the court is as good as rebound. Adebayo made sure his man, Jaylen Brown, couldn’t get a clean catch then, when Smart caught it, cut off the driving lane. When Smart’s shot when up, he turned and boxed out Brown. He handled his business.

“Trying to force the ball away from the basket,” Adebayo said of Miami’s strategy on the play. “(Smart) missed a shot and guy ran in and got a layup.”

Should Spoelstra have called off the double and had Strus play his man straight up? Easy to say in hindsight. Had Tatum gotten a clean catch and made a shot, critics would have asked how he could allow Boston’s best player to take that shot.

This was just a freak play born out the chaos of a highly-competitive game between rivals. Credit to White for making a historic play. Here’s how White explained it after the game.

“I was passing it in. (Gabe) Vincent was on me, and he kind of was up top denying (Tatum), so I couldn’t get him the ball, and they did a good job of denying (Brown), too and Smart flashed, hit him, and there really was nobody on me. So I just spaced to the corner and, when he shot it, just tried to crash. Ball came to me, I made the shot. That’s what I saw.”

There’s also the matter of how much time was left on the clock: 3.0. The official last two-minute report will be out Monday, and it’ll be interesting to get an explanation as to why 0.9 seconds was added to the clock after Butler’s free throws were made with 2.1 seconds remaining. When the officials looked back, it was determined that Horford’s initial contact on Butler was made at 3.0 seconds left. Anything less than 2.9 seconds, and maybe White’s shot is late and the Heat are preparing a trip to the Finals.

Whatever the outcome of the last two minute report, it should never have come down to this. A week ago, the Heat were up 3-0 and the Celtics looked mentally broken. They’ve lost three games in a row, including now two at home.

On Saturday, Butler played his worst three quarters of the postseason, missing 14 of his first 16 shots. He didn’t make his first field goal inside the arc until two minutes before halftime.

“I told the guys in the locker room,” Butler said, “that if I play better, we’re not even in this position.”

Butler will have to play better on Monday to render White’s miraculous tip-in meaningless and help the Heat avoid making the wrong kind of history.