I don't get people that argue at drive thru windows. Like, it's never that serious.

It's a damn fast food restaurant. The tacos aren't even that good at Del Taco.
I kinda feel bad for the manager because the couple most likely started the argument by being assholes. Customers have a terrible sense of entitlement especially when it comes to restaurants, and they are encouraged to be that way in America with phrases like "the customer's always right" when they literally are not. In fact, most of the time, the customer is wrong, and just being whiny.

Obviously it was tacky of the manager to act out, but still.