> That's generally where courts draw the line between helping out a friend, and providing a service.

The point is that it isn't the same service being provided and they are very upfront about that with the customer.

When you provide what is legally considered to be a service, it comes with legal guarantees. You don't generally get to escape by saying something doesn't count, no matter how upfront about it, that you are. Consumer protections exist, regardless of whether you say they shouldn't apply.

One of the guarantees that probably applies in this situation, especially as it is California which tend to have a few stronger guarantees, is fitness-to-purpose. If there is a service, where an exchange is taking place, there is a guarantee that the product should be considered fit-to-purpose.

> The warranty of fitness for a particular purpose is not limited to sales by a merchant as is the warranty of merchantability. It may be imposed on any seller possessing sufficient skill and judgment to justify the buyer’s reliance. The Code drafters suggest, however, that a nonmerchant seller will only in particular circumstances have that degree of skill and judgment necessary to justify imposing the warranty.” (4 Witkin, Summary of California Law (10th ed. 2005))

The products themselves are unmarked, which means it doesn't matter how upfront that they are with the first customer, because the product is allowed to be resold, and then the limitation on purpose aren't guaranteed to be seen anymore, but it needs to be, if you want to reduce your liability.

As noted in many other places, the very lack of a mark is exactly why these cannot be used in places where they have to be certified. Anyone that accepts it in that case, is in the wrong.

And you do get to escape liability with disclaimers quite well. Just look at every tax reporting agency out there. Massive disclaimers about how you are still liable for any mistakes they may make.