I don't think that the NBA is really all that concerned with "making it right" with Hansen. At least to a point. If I'm looking at it from an owners perspective this is the best case scenario. Hansen will be used as leverage for as long as they can string him along.
Basically, get Hansen his 30 million back, and tell he he needs to be patient and his time will come, either through expansion or a move. As long as you can keep him on board by dangling that carrot, the next time that a city doesn't want to pony up for half the cost of an arena, it won't be about the city vs their owners, it will be about the city vs what will happen to their team if they don't, since everyone knows there is a Big Bad Wolf out there who will offer a huge amount of money to get his team.
Of course this cant go on forever, sooner or later Hansen will get tired of being the leverage, but he has made his bed with Seattle and portrayed himself as the savior who is going to bring the NBA back to Seattle, so he will stick with it longer than say Larry Ellison, who the NBA tried to use the same way but he wasn't in it as deep and has seemingly lost interest in the whole deal.
So all in all the NBA is trying to keep the kings in sac with a record sale price, created by Hansen, and not pee Hansen off or cost him any money. And do just enough to keep him on board for the next time this situation rolls around, and at that point it a city fails to do their part Hansen will get his team.