First of all, the clapping by bench personnel is perfectly legal. Bench personnel can legally clap from the jump ball until the final buzzer as long as it's not taunting (and if it doesn't distract free throw shooters, a controversial topic here on the Forum).
Regarding bench personnel standing. Technically it is illegal by the written rule because it wasn't spontaneous and doesn't appear to be a reaction to an outstanding play by a teammate (bench personnel not immediately sitting down doesn't apply since the game ended).
But we don't just officiate by the written rule. We have to
know the intent and purpose of a rule so that it may be intelligently applied, in this case
to create an atmosphere of sporting behavior.
Being around basketball for over fifty years as a player, coach, and official, I know unsporting behavior when I see it and this isn't unsporting behavior.
It doesn't appear to be taunting. With seven seconds left in the game, it doesn't even deserve a written warning, or a warning of any type.
That being said, I do appreciate Mike Goodwin being a true guardian of the game, as all good officials should be. This behavior got his antennae tingling, and he decided to give it some careful thought.
Maybe things are different in the "Land of the Midnight Sun", but here in the "Land of Steady Habits" this wouldn't even register a blip on our radar screens.
Here in Connecticut we use radar to land airplanes and to follow storms, not as Alaskans do to warn us about incoming Russian bombers and missiles.