Has that actually ever happened? Lockpicking Lawyer shows most locks are almost effortless to pick. The same locks sold by the millions to all of us.
Even so of course we know there IS liability for some things and maybe just locks are not a good example.
But then maybe that just means that security itself is not a good example and the authorities are being inconsistent by going after security only in software.
Or maybe it just means the liability should not be just security in general, but responsibility for when you hold something for someone else.
Most other forms of liability are for the safety of an object sold to the public, or it's very basic functionality. If a normal expected use of a lock cuts peoples fingers off, or if it fails to latch at all, not if it is easy to defeat.