Is Cuban "just" a fan during the game? *NO*. He's an OWNER, meaning that he has additional responsibilities, and therefore, should be allowed some latitude.
If I'm paying millions of bucks for a player to play for my team, if that player gets hurt, I want to know IMMEDIATELY what's going on. I don't want to wait until after the game, and I'm not going to wait around for someone to remember, "Oh, we better tell the owner what's up." I'm there, so I'm going to go find out, because this potentially necessitates action on my part - perhaps acquiring a new player, or pushing through or holding on a trade that we've got in the works. It may even require me to interact with the league office.
I cannot buy the idea that Cuban is "just" a fan. If that were the case, some of the actions for which he has been fined - such as CRITICIZING OFFICIALS in a loud and public manner - are invalid; I don't know any of us who are opening our checkbook up.
That said, he is one of the folks required to help make the game run smoothly, and therefore, is under the jurisdiction of the *GAME* *OFFICIALS*, as well as the league office. In other words, just because he's not on the bench, a game official can *STILL* charge him with a technical foul, can still eject him, and these things SHOULD be done if he interferes - especially in stepping onto the court. The NBA has penalties for players and coaches; those same penalties apply to Cuban.
A fan stepping onto the court would be arrested. Cuban stepping onto the court *CAN* be claimed, that as an owner, he has that privilege, and many folks on a jury - including me - would buy that logic, especially since he's paying to put on the game. You cannot apply the same rules to an owner that you do to a fan. However, there *ARE* rules that govern Cuban, and he's seen that no one truly UNDERSTANDS those rules, and as such, he's pushed the envelope. We don't have problems when players or coaches do such things; if a player sees that referees aren't enforcing hand-checks, you can bet your bottom dollar that the player will intentionally use more hand-checks. It's smart basketball, right? So what's the difference with an owner pushing the envelope? The fault isn't Cuban's - it's the lax execution by the game officials and the league office.
Cuban is *RIGHT* not to respect the game officials. Their failure to control *HIM* is the ultimate validation of the criticism that he's levelled against them. Until that situation is remedied, I'm on Cuban's side on this one.