Yes, that was a mistake, and they said it was a mistake, and they won't do it again. So you can't use this as a general example of how amazon behaves - unless you are arguing they listen and try to fix mistaken behavior.
No matter how benevolent Amazon may be, it is still problematic that, when you "buy" an ebook with them, they are technically able to remove it from your ebook reader. This is bad even if they only use this power when they mess up or when they are legally compelled to do it (an option they still explicitly allow for). So even if they apologized and promised not to do it again, the point still stands...
