[vanderZwan]

You complain to GP for not considering that the people who published the original Marshmallow test paper had controlled for confounding factors. In the opening paragraph, other researchers complain about just that.

In other words: a more sensible reading of GP's comment would be as a reaction to said paragraph.

[MikkoFinell]

I asked why OP is dismissing the possibility that the authors considered the specific factors OP mentioned.

The quote you posted did not address that question. That is why it is not related to my comment, like I already said.