Make it compulsory to declare allergenic ingredients in alcoholic distillates

I bought my boyfriend some chocolates for Valentine's from a well-known chocolate shop. He has a severe nut allergy and has been hospitalised before. I checked the ingredients many times and asked staff to check - nuts weren't listed as an allergen. On opening the chocolates, one contained hazelnut liqueur - which by law doesn't have to be declared as an allergen. This is dangerous, and could have killed my boyfriend. Action needs to be taken so derived products also have to declare allergens.