Went to an Indian restaurant in NY, the waiter was awful not just bad but an asshole, we left without tipping and the manager ran after us telling us we had to

Went to an Indian restaurant in NY, the waiter was awful not just bad but an asshole, we left without tipping and the manager ran after us telling us we had to tip or he would call the cops. How about you pay your damn employee or fire him for being incompetent?