It wasn't because they dreaded watching the ceremony, they insisted.
They were simply getting ready to show everyone why they are favoured to win it all this season.
James and Wade led a series of scoring waves that put Miami ahead by 35 points midway through the third quarter, the lead peaking when James soared to the rim and tipped an alley-oop pass to Wade so he could have the dunk instead. The game was essentially over then, although the Mavs reserves fuelled a late rally that made the final score look close, 105-94.
"We tried to play aggressive," James said. "We're a focused team. We had a great training camp. We came in with the same mindset we had at practice, use our speed and play with mental focus."
James finished with 37 points, 10 rebounds and six assists. Wade had 26 points, eight rebounds and six assists. Miami scored at least 30 points in each of the first three quarters.
"Celebration or not, we had a game plan and implemented it," Wade said. "We came out and played a good game."
Maybe the pregame festivities left the Mavs emotionally drained because they were down by 15 after one quarter and 21 at halftime. They then gave up 14 straight points early in the third quarter.
The blowout had less to do with an emotional hangover and more to do with exposing the slow process of breaking in a new rotation. Dallas lost centre Tyson Chandler and backup point guard J.J. Barea and added guard Vince Carter, do-it-all Lamar Odom and backup guard Delonte West.
"We're going to have to forge an identity with this team; it's a different team," Mavs coach Rick Carlisle said. "That's work, and it's going to take honesty, and it's not going to be easy."
Carter took Dallas' first two shots, an 18-footer and a layup. Both missed. West started the second half in his place and finished with 10 points. Carter had five points, two rebounds and three assists in 21 minutes.
Odom — the NBA's reigning Sixth Man of the Year, who was acquired from the Lakers a few weeks ago for merely a trade exception — entered to a standing ovation, and got fans roaring again when he made a three-pointer that tied the game at 11. He missed his next five shots before getting ejected midway through the third quarter, but still left to loud cheers. He had four points and four rebounds in 13 minutes.
"We've got to get better and it will take a little time to get better," Odom said.
Jason Terry sparked a Dallas rally, that started after Odom was tossed, and wound up leading Dallas with 23 points. Nowitzki scored 21 in three quarters. Shawn Marion scored 12 and broke the pinky finger on his left hand.
NBA commissioner David Stern attended the game and took part in the banner raising ceremony. Fans greeted him with boos, perhaps showing disgust over the lockout that delayed the start of the season from Nov. 1 and shrunk the season by 16 games.
Fans had plenty more to cheer, such as Terry proclaiming, "Thirty-one years you waited — 31 years! — to call your team a champion, ladies and gentlemen. A champion!"
Nowitzki, Terry, Jason Kidd and many more players, coaches and staff each got a strand to yank as part of the unveiling of the banner at court level. Nowitzki and Kidd seemed awed as they watched it rise to the rafters. They couldn't take their eyes off it — or didn't want to.
Championship tie-ins were everywhere, from the Mavs' warmup jackets proclaiming them the 2011 NBA Champions to jerseys featuring a patch of the championship trophy, with the words on the front and back of their jerseys all outlined in gold. Terry even wore gold high-tops.
But Dallas was more style than substance, especially compared to a Miami team that returns the core of its rotation.
The Heat scored 18 points in the paint in the first quarter, while the Mavs scored a total of 17 that period — none in the paint. Both Miami's 18 and Dallas' 0 are an indication of how badly the Mavs will miss Chandler.
Miami went on a 12-0 run late in the first quarter, a 15-1 spurt in the second quarter, then the 14-0 binge in the third period. At the end of that final surge, James made a spin move to free himself for a 17-foot jumper off the glass, then followed with his alley-oop tip to Wade.
"It was showtime," said Heat point guard Mario Chalmers, who had the initial pass to James. "That comes from playing a whole season together last year and working out during the off-season with each other."
NOTES: Miami had lost 14 straight regular-season games to the Mavericks and nine straight in Dallas, dating to March 2004. ... The Mavericks were sold out for the 400th straight regular-season game, extending their NBA record. ... The championship-defence-opening rout might seem familiar for Heat fans. After Miami beat Dallas in the 2006 finals, the Heat were clobbered 108-66 at home by the Bulls in the 2006-07 opener. ... The Mavericks had fun connecting Christmas and their championship, such as a parody of "The Twelve Days of Christmas" that kept coming back to the line "and a Larry O'Brien tro-phy." ... The Heat showed their holiday spirit by wearing green laces with their red shoes.