In the US, at least, there's some minimum amount of liability that you're not allowed to get out of in many cases.

The act of creation and distribution of something, regardless of its cost, imparts some measure of liability on the creator. You made it and you gave it to someone, or put it somewhere where someone could reasonably take it with your approval, which leaves you responsible in some measure for the performance of the thing. The law sets a minimum amount of liability you can have and, while you can go over that (by claiming that your creation does particular things), you can't go under it.

This isn't, on the whole, a bad thing. It ensures that the manufacturers of things take at least a minimum amount of care in the production of whatever they make. I'm pretty sure that doing due dilligence and making what would be considered the best reasonable effort will limit your liability, but that's something to check with a lawyer about.