Cross-contamination! They offer gluten free crust but since they make their regular dough in house, there is wheat flour dust covering everything.
Disclaimer: I am only gluten intolerant so I can only speak for those similar to me. I don't have an issue with cross contamination either. This place was amazing! I got a plain cheese but next time I plan on adding in some veggies. The staff could be more knowledgeable on gluten - I asked if the sausage topping was gluten free and he didn't know so I didn't get it. However, my pizza tasted amazing and I had no issues afterwards! I can normally tell within minutes.
They always take fantastic care of me - I ask them to change their gloves, get new sauce and ladle, wash a pan for the pizza itself and they do all of it without complaint. Just let them know you have an allergy and they will warn you the stove isn't gluten free and there can be cross contamination.