I agree that not listing every oil spill isn't required to make a view American centric. That's not the issue though, it's a straw man. What's American centric is to focus on America even when similar things exist elsewhere.
You misunderstand what Americentrism is. It is about the presumption of US morals and standards when judging other countries and cultures. Some would say that your use of the word "America" to describe the United States is itself Americentrism.