Well the issue here is that the bug can cause you to die or can fuck up your entire life. A software bug generally doesn’t do anything to you and you actually don’t pay much money for software.
One false diagnosis from a doctor costs you thousands of dollars and fucks up your life.
Remember mcas? The bug on the 737 max that forced Boeing to pay reparations? That’s the level of bullshit people are dealing with for doctors. Life altering stuff. This isn’t some chrome bug or smart phone bug. Therefore the penalties and repercussions of mistakes should be equivalent.
If the diagnosis only costs 100 dollars or something, and I was told that the diagnosis was only a probability… I could accept a no refund policy in that case.
Legally speaking, why should the rules for important services be different than unimportant services. The price paid for the services is proportional to its value, if there are no consequences for a bug in your code, it was worth less and you should have paid less for it, the refund would be commesurate.
It's worth noting that you framed the discussion in terms of refunds, so any extra human life uncalculable value isn't really within the scope of a refund, you'd have a malpractice case which is entirely different from a breach of contract. This is just about the fees paid for the service.