What you call ‘grey areas’ is another way of naming the sorties problem (or boundary issues)
When, for example, does a child become an adult. In law, this occurs at a specific point in time. Before that point, a child; after that point, an adult. In reality, we know that the transition from child to adult is a process that itself takes time. At age 5, child; at age 25, an adult. Somewhere in between, the change takes place. The sorties problem is often used in argument to argue that if we cannot point to a bright line point of transition from A to B, there’s really no difference between A and B. That, of course, is nonsense.
let’s see how we deal with this in practice. If your neighbour is having some friends over and they’re having a barbecue in their back garden, your likely to hear some sound and smell some hamburgers cooking. Is this an invasion of your rights as a property owner? Most people would say no – that’s what you get when you live adjacent to someone else: a little noise, some smells, etc. However, now let’s have the same party take place at 3 a.m. when you’re trying to sleep. This time the noise prevents you from sleeping. Do we now have an invasion of your rights as a property owner? Most people would say yes.
What does all this tell us, if anything?
We have and exercise our rights in a context of social conventions which are rarely completely (sometimes never) realised in law. Most properly socialised people understand and abide by those conventions and that’s what makes life together possible.