Yea sorry, meant civil law.
Murder is kind of hard to use as an example because there's typically really strong moral and cultural understandings that you shouldn't be doing that. But lets think of a more nuanced example. Lets say there's a lake that's being overfished. The government doesn't want to outlaw all fishing, but they want to rein in the more massive fishing operations. So they outlaw using trawler nets in the lake, but people using conventional poles or spears can keep fishing as much as they want.
Now say someone comes along and figures out another method to massively overfish the lake without using nets. In civil law countries if the law is written to specifically outlaw the use of nets I think the people would look at the law as faulty instead of the person who exploits the loophole. After all, whatever method they figured out isn't actually illegal. And the way to solve the issue is to update the law, not to punish the clever loophole seeker.
But in common law countries the law would more likely be written in a way that can't be as strictly interpreted. There might be wiggle room that would allow a judge/jury to basically say "Look we didn't explicitly forbid what you are doing, but it's clearly something this law was meant to prevent. Therefore you're guilty, and case law will be updated to include this verdict."
At least that's how I interpret it.