I'm one of those that said toss him.
But understand, he wasn't coaching. He was a fan during the poor behavior. And as a fan, he was likely allowed more leniency than a 'regular' fan because he was also recognized as being a coach.
If you kick a fan out, I think it is generally accepted that they are gone for the evening. End of punishment. But of course this is enforced by game/facility management - they will likely be willing to let the 'coach' back in to next the game.
Kick out a coach different story. Here are the rules from backwoods Idaho (with pieces missing) for ejection of a coach. You can see them in their entirety at:
http://idhsaa.org/rulesregs/home.asp under General Rules and Regulations, Section 4-3.
Here are the high points:
In any athletic contest, ... any coach ... ejected by an official for unsportsmanlike behavior will be suspended for the remainder of the Contest ... and, will be suspended for the next regularly scheduled contest at that level of competition and all other games/meets/matches in the interim at any level of competition. ...
The responsibility of enforcing the penalty for being suspended is with the school principal. Any dialogue concerning the suspension should come from the school principal and be directed to the President of the District Board of Control.
...The game official that disqualifies an individual for an unsportsmanship-like act must notify the District Commissioner with a written report by the conclusion of the next day. The District Commissioner, upon receipt of the report, shall notify the District Secretary, President of the District Board of Control, the school, and the IHSAA with a written report of the incident by the conclusion of the next school day.
When an individual is suspended for the next contest under Rule 4-3, the interpretation of contest is referred to as the following: ...
Basketball: next game
4-4 If a coach is ejected from an IHSAA contest, the designated school administrator must appoint an appropriately qualified adult to supervise the remainder of the contest or forfeit the contest.
Of course none of this paperwork stuff is done for ejection of a fan. In the case cited by Juulie, the fan/coach calls the Commissioner; Commissioner tells the official to stand down; fan re-enters the contest now as a coach.
In my opinion, it's got to be pretty bad stuff to eject the fan/coach. But two fans, all alone in the stands on one side of the court; standing, pointing, and yelling at an official would be impossible to ignore, and again in my opinion meets the definition of "pretty bad stuff."
Whether he stays out for the next game... I don't know. I personally wouldn't stick around to find out and I sure wouldn't be enforcing anything. Perhaps the game management would feel the same way as did the official and keep the coach out in the cold. Perhaps not.