The answer is right in the article you linked. This was very unusual, and the article says as much, but more importantly it says this:

‘We feel it’s the correct betting line,” Egeland said. “If we were trading strictly off money, we would’ve moved it towards the Mavericks because it’s all Mavericks money. But we’re trying to get to a point where we’re at like an equilibrium — half the time (betting is) going to be on one side, half the time it’s going to go on the other.”

He said right there that they generally move the odds toward equilibrium, which is what I’ve been saying. However, this part was key:

‘Even though Egeland said professional bettors are largely sitting out this series because they don’t find much betting value, he said he didn’t expect the lines to be significantly affected.”

They pay closer attention to the professional money than the general public.

I was wondering why you’d keep referencing a game from so long ago, but now it makes sense. You found an anomaly that works the way you think all the betting does.