Liability is still clear, and in the specific case of medical practice, a degree of "we can't foresee everything" is implicit in that our understanding of the governing principles of the human body is incomplete.

Aviation does not have that excuse. The 737 MAX 8 system description is enumerated from the ground up. Seeing as there was so much recertification effort that didn't need to be done, it makes the failure to properly handle the MCAS implementation all the more damning.

This wasn't some subtle bug. This was an outright terrible design choice. Anyone with any experience composing complex systems out of smaller functional building blocks should have been able to look at the outputs, look at the inputs, and realize there was the potential for catastrophic malfunction.

As I've said elsewhere, automation should make flying a plane easier when functional. When non-functional, however, the pilot should still be able to salvage the plane. That requires clear communication of what automation does, and what it's failure modes are.