[lutusp]

The paper (...) is not an example of good science.

Very true, good point. It's quite common to see a study that makes some observations, even rigorously controlled ones (this isn't an example), then offers a conclusion that isn't supported by the observations. People untrained in science notice the quality of the observations and think that supports the conclusion.

In this case, a correlation is established, then, when evidence for a cause-effect relationship is needed, the authors instead begin waving their arms.