He is at risk either way. If your mother comes over for dinner and you serve her undercooked chicken you could be at risk of a lawsuit.
If you cook for a church, you as the cook and the church could be liable. You could be liable for preparing the food incorrectly and not being sufficiently licensed or certified (i.e. Servsafe) to prepare the food. The church could be liable for not verifying that you were licensed or certified or negligent for knowing you weren't and selling the food.
And the having people over for a party analogy is bunk. You are at risk when anyone is at your home. If you own your home or have renters insurance, you have a policy limit in that coverage to protect you for injuries to others in case a neighbor comes over for a BBQ and falls off your deck and breaks their leg. Or a kid slips on the icy sidewalk out front of your house after a snow storm.
The church reference brings up a good point that many people have tried to use as a tool before. Some states have food safety or vending exemptions for non-profit organizations that do not require them to obtain temporary food permits. This does NOT apply to someone who cooks food on behalf of an organization. For example, if you are a regular attending member of a church and you volunteer to cook a church dinner in their kitchen, etc then you may be covered under that exemption if your particular area does have an exemption. But you cannot cook food off premises or for a church you have no affiliation with and circumvent the rules.
The contest we organize in Franklin is run by a non-profit organization and the county health department in our county requires us to pay $30 per team that participates in the People's Choice competition to obtain a temporary health permit because even though the event is run by the non-profit, all proceeds go to the non-profit, the food is cooked by people not in the non-profit so the exemption doesn't apply.
I'm not saying that's how it is everywhere, but spending hours and hours trying to find a loophole isn't the right way to go about it. Doing it the right way protects you and promotes a professional image to your patrons. In this day and age where everyone sues everyone anyway, it is even more important to be insured and formally organized to protect your own behind.