That's a broken argument since what they are stating is that a higher law was broken. It's also not always the case that laws do not apply retroactively: https

That's a broken argument since what they are stating is that a higher law was broken. It's also not always the case that laws do not apply retroactively: https://en.wikipedia.org/wiki/Ex_post_facto_law https://en.wikipedia.org/wiki/Ex_post_facto_law