What are three other alternatives to quitting his job that Sammy could have done?

Sammy quits his job at the grocery store in a misguided attempt to look noble in front of three teenage girls who the manager reprimands for coming in wearing nothing but their bathing suits.
Sammy meant well, but he could have stopped and thought for a moment about more effective alternatives to his rash action. He could have followed the girls out for a moment (no doubt risking getting in trouble) to say he thought they should be allowed wear what they want in the store. He could have also said the same thing to the girls in front of the manager, showing them his support.
Another alternative, though less satisfying in the moment, would have been to speak with the manager later in the day, perhaps at closing, to express his feelings. He could perhaps have tactfully communicated that lecturing customers is not good for business. Sammy also could have suggested that a dress code be prominently displayed in the window of the store so that people would have a better idea what to wear.