The barbecue is sauced before it hits your table
To cover or not to cover brisket in sauce is a customer's inalienable right. So, it's not only presumptuous of the joint to shellac your meat in their "award-winning" sauce without asking, but it's also a crutch used to hide all manner of barbecue sins. A dark, sticky, liquid smoke-infused sauce can cover up foreign flavors (think lighter fluid or propane), or meat lacking the flavor of real smoke. It also masks the bleak, grey appearance of meat that has been wrapped in foil, reheated, and/or steamed flaccid. The same goes for any restaurant that frolics in the kind of "our sauce is boss" chest-bumping braggadocio you see on Food Network cooking competitions. If the sauce gets more airtime than the meat, something ain't right.
There's no wood stack in sight
By definition, barbecue is made by the intermingling of meat, wood smoke, and fire. If there's no sign of cooking wood in plain sight or no distinct smell of smoke in the air, then there's no barbecue in the house. And I don't mean sacks of sawdust that the restaurant sprinkles over a fire to create the illusion of wood smoke. You want to see a cord of oak, pecan, hickory, mesquite, or any other type of smoking wood stacked or piled somewhere in the proximity of a hulking, smoke- and grease-blackened pit. In barbecue, using gas, electricity, solar power, wind turbine, or any other primary heat source other than wood on fire is a big no.