Potato starch vs flour

I was looking on line for some spicy chicken recipes and came across PF Chang's menu on line (with ingredients in ea dish) and a web site that listed their recipe as PF Chang's. The carb count was high, real high for spicy chicken appetizer wrapped in lettuce leaf. It called for potato starch to dust the chicken in. Potato starch is much higher in carb count then flour, per my research. I am eating low carb so found this very interesting. Do Asian dishes typically use potato starch? I would have thought I could eat all that and be in my low carb zone. NOT!