Intent intent intent. The analogy of grabbing the binder on the back counter fits perfectly, because it shows the intent.
Googlebot is incapable of intent. It is a computer program that simply crawls accessible pages. It cannot distinguish between a website for which access is obviously not intended (i.e., Weev's case of accessing *other people's private information) and a website for which access is intended (i.e., a public Facebook or LinkedIn page).
Someone has to use Googlebot though. Google is therefore liable for what it does. Just because a machine or a piece of software is the main actor does not mean there is no culpability.
Google is trying to index as much of the web as possible so that it can provide a better service, attract more customers, and make more money from its advertisements. Therefore, the use of a program that scans the web and accesses documents which Google does not have permission to view makes Google responsible for routinely and intentionaly breaking the law.
Also, that your tool cannot filter content particularly well does not mean you get a free pass. It means you were negligent.
...or at least that is one way to interpret the law. The law is bad. You can't just say it's illegal when its illegal. It should be as cut-and-dry as possible (e.g. killing someone is always illegal, even when it is an accident a la accidental manslaughter).
Googlebot is incapable of intent. It is a computer program that simply crawls accessible pages. It cannot distinguish between a website for which access is obviously not intended (i.e., Weev's case of accessing *other people's private information) and a website for which access is intended (i.e., a public Facebook or LinkedIn page).