Maybe you’d hand the drink back to the bartender and say, “Hey I’m really sorry, I just ordered this and I know this isn’t your fault but a bug just flew into my drink, do you think you could make me another one?”
Or you could do what the “Margarita Karen” did and toss the beverage at the beverage maker behind the counter.
Source: https://www.distractify.com/p/margarita-karen-throws-drink