Ethical questions

Was the developers ethical?
I think what they did is wrong, but what can you do about it. The original owners didn't about what they can do with the land and they just sold it to the developers for only 7.2 million, while the developers made much more money from the land. To me this is ethical, they didn't break any laws, they were just clever by know the law.
How can this be avoided in the future?
This can be avoided by knowing what you can do when something like this happens instead of just selling it. You can use a lobbist like what the developers did. You can also avoid buying property that will cause you problems.