As far as Islamic Shari`ah is concerned, a Muslim is allowed to eat halal (lawful) food prepared by any human being as long as it is clean, healthy, and prepared with halal ingredients. A Muslim is required to eat what is halal (lawful) and tahir (wholesome). So, if a Muslim wants to eat in a restaurant that serves halal and non-halal food, he should be keen to make sure that he eats halal items.
Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states: If a Muslim takes bacon unaware and mistakenly, they need not feel guilty; for Allah does not take us to task for such slip-ups and unintentional acts. Prophet Muhammad (peace and blessings be upon him) also said, “My Ummah is excused of their unintentional mistakes and forgetfulness as well as what they are coerced into.”
So, as muslims we simply need to ask forgiveness of Allah and make sure in the future that we eat only at places that we can trust. It may be a good idea to avoid altogether places where they serve haram items as well as halal – provided that you have alternatives.