You're right, in the case that it was known to be a problem. There are lots of places where the "<= or <" decision can be made, some long before some guy opens a text editor; in those cases, the unit test might not catch anything because the spec is wrong!
A major difference between software development and engineering is that the requirements must be validated and accepted by the PE as part of the engineering process, and there are legal and cultural rails that exist to make that evaluation protected, and as part of that protection more independent--which I think everyone acknowledges is an imperfect independence, but it's a lot further along than software.
To fairly impute liability to a software professional, that software professional needs to be protected from safety-conscious but profit-harmful decisions. This points to some mixture of legislation (and international legislation at that), along with collective bargaining and unionization. Which are both fine approaches by me, but they also seem to cause a lot of agita from a lot of the same folks who want more software liability.
> in those cases, the unit test might not catch anything because the spec is wrong!
That's why you have three different, independent parties design everything important thrice, and compare the results. I'm serious. If you're not convinced this is necessary, just take a look at https://ghostwriteattack.com/riscvuzz.pdf.
(Your other suggestions are also necessary, and I don't think that would be sufficient.)
A major difference between software development and engineering is that the requirements must be validated and accepted by the PE as part of the engineering process, and there are legal and cultural rails that exist to make that evaluation protected, and as part of that protection more independent--which I think everyone acknowledges is an imperfect independence, but it's a lot further along than software.
To fairly impute liability to a software professional, that software professional needs to be protected from safety-conscious but profit-harmful decisions. This points to some mixture of legislation (and international legislation at that), along with collective bargaining and unionization. Which are both fine approaches by me, but they also seem to cause a lot of agita from a lot of the same folks who want more software liability.