Actually this doesn't mean law is impossible to map into a computer system, just that the work to do it would be next to impossible to undertake. "Spirit of the law" is exactly what? A desired goal but impropertly worded.
Once you assign granularity to concepts you can map things. Who does more damage, a lady stealing some products off the market's shelves or a crook laundering money? Who does more damage, a kid coming to school with a shotgun or a kid with two pistols?
Putting concepts into computers means that they NEED to be precise. One reason why lawyers are not happy with computer systems - they bring clarity in a field where speaking legalese is actually a feature, not a bug.