Liquor Control Board of Ontario [LCBO]

My daughter, son and I were shopping at the store in question. My son was carrying the basket and we were all adding items to it. When we got to the cash my daughter (27 years old) presented her ID but my son (20 years old) realized he didn't have his wallet. He left the store and went to the car. We explained that he didn't have his ID but that I would make the entire purchase. I was refused service with the explanation that they didn't know if I would then be giving him the alcohol. Regardless of my behaviour once I have made the purchase I don't see how they have the right to refuse me service, or my daughter for her items in the cart. I fully understand the need to restrict alcohol sales to minors but I feel that they overstepped their authority in refusing me and my daughter service. We were not even given the option of replacing his items on the shelf and proceeding with our purchase. I understand that they can refuse to serve someone without identification but not how that translates into everyone in the group. As a government owned entity I would like to think that we can police under age drinking without becoming tin pot dictators who can arbitrarily refuse service to those who are entitled. We will never return to that store and look forward to the day that regulations are changed in Ontario and the LCBO is permanently dismantled.