My understanding is that the seller is responsible for the condition of the product at the time of the sale and for some term after as determined by the courts. Mere transfer of product from one's hands into another's hands, independent of any $ transferred, is a sale (just ask an old hippy or poor city kid about this one
) I don't think the courts will see much difference between product and service, both are stuff the seller is generally presumed to be more knowledgeable then the customer.
I do see some wiggle room for the "good Samaritan" acts But advertising or charging for stuff pretty much eliminates that one. Andy