If you're not an expert in the field and manage to find a more or less obvious mistake in the research of the article, how many more subtle errors an expert would find?

Actually that is not the case here. The article is an overview bringing together ideas/opinions from various different researchers only one of whom seems to have employed questionable practices.

Seriously. People oft forget there are two parts to critical thinking: the part where you figure out all the ways something could possibly be untrue, then the part where you figure out all the ways in which it could be true.

This. even the most flawed highschool level proof of gravity is still probaly correct.