But we are not liable as long as we follow standards, e.g. building codes. And it's easily verifiable by the government, the employer and the engineer himself whether the standards are being complied with.
Until you have similar standards for software development, I cannot see how such liability shift could work. This is one of the reasons I tend to avoid using the phrase software engineering. It's so different from traditional engineering that it feels incorrect to put it in the same category.