That bias can't be erased no matter what the system of laws are, but I think allowing a full accounting of events for the judges ends up in more fair sentencing. I have also looked at a study that showed judges hand out harsher sentences after being reminded of their own mortality.
The law just can't be extremely precise.
Taking speeding for example. It is against the law to speed, but should you really have to get a ticket if you are rushing to the hospital.
Not really and it's not written into law, in your example the person has to pay a fine, but with case law, a fair verdict can be made and when somebody speeds to get away from a serial killer, we can determine a more fair result based on that previous case law, than by having hard rules that can't be altered, even though the world and language is constantly evolving.
Words are really just abstract things, by the nature of the human language you can't even get as specific as possible to avoid some unthought of exception to a law.
Even if you could possibly do so, the amount of research needed to create a perfect law would take billions of dollars, when you can just get perfection through trial and error