I always try to avoid from having some silly argument, especially at the public places. When something so small and ridiculous comes up, and you handle it like a debate in the parliamentary level, it actually shows how dumb and ignorant you are to all other people who keep staring at you like some live drama is going on. The best way to end it quickly is just nod politely (even though you're not agree with it) and just keep your mouth shut.
Ps : My berbuka meal today got ruin because of some stupid couple arguing with each other that happened just next to my table. And when they decide that shouting and arguing with vile words are just not enough, they start to throw plates and glasses from their own table and one of the plates hit my eye. Damn !! It really hurts, you know.