Likewise, what the computer does is irrelevant, except insofar is it tells you about the owner's intent. So the question is not "did the computer let you access the file." But "what does how the computer let you access the file tell you about what the computer owner intended?"
Also, I'm not sure your analogy works at all. In the first paragraph, you seem to analogize the car to the accused "hacker", while in the second you're talking about the supposedly "hacked" host. To be clear, the point of the car example is that a machine's intelligence has no bearing on how its actions affect the duties of its operators.
The best, and most accurate, way of determining if the resource you requested is meant to be accessible, is to check to see if you got a 200 OK response or a 403 Forbidden response.
So your argument is that a better way to check this is to crawl the entire web looking for links to a resource to determine if it was meant to be publicly accessible?
Your intent argument is really shallow. People do bad things with good intentions all the time. Doesn't mean their actions are good or legal.
Or you failed to follow the rules, were careless, and hit him by mistake. Was your intention to kill him? No. Was it your fault? Yes.