But I like your example. Because in a well organised OR, the doctor cannot leave a scalpel inside the patient all by herself. The nurse would have to fail to properly count the instruments at the same time. BTW: all non-metallic objects have embedded pieces of metal that will show up on X-ray, so errors can at least be detected. Do they let plumbers operate on patients because it's now much safer? Not where I live, the laws are pretty strict with respect to who can practice medicine.
If you want safety, stop thinking in terms of blame and vengeance and design systems that avoid errors, and reduce their impact if they occur. This includes culture, processes and tools to protect against errors by those who do the work, and some regulation to stop management from putting employees in situations where they are likely to cause harm.
Those measures have made aviation safe, and medicine is catching up. Time for the software industry to mature.