Maybe the problem here is the 24k.
He thinks he is indispensible.
As my dad always said,
"the graveyards are full of indispensible people"
I would have suspended him for the day, take it out of his bonus and have a chat about his future the next morning. His attitude next day would decide whether he stays or goes. If the other guys see him getting away wioth that kind of stuff, they will soon lose respect too. You are the boss, they are the worker. If they forget their place then that is a problem IMO