What do you call someone who is focused too much on the technicalities of a law rather than the big picture? Some people are too much focused on the word by word definition of a law that they forget why these laws were put into place and use the definition to apply the law in a way it wasn't intended by the person who wrote the law. Is there a word for such person? You can use related words and maybe form a short phrase if there isn't any word for it.
For example:
The ____ used a technicality in the law to bypass it entirely.