I think the study is completely unable to differentiate between a word being gender-neutral or not and the actual concept of the word having a strong gender-based stereotype. Industrial Man--that's a male, all the way. I don't care HOW you present the concept of Industrial Man, whether it be lexically, pictorially, auditorily--you're going to get a bias because the actual concept has a gender-specific stereotype.
The study TRIED to deal with that issue by using related words (like Industry), but these words evoke absolutely no image of people at all; they are more abstract. They're not good choices to counteract the issue described above.
Better choices of words would contain the word "man" but refer to a concept that is gender-neutral. If there were such a word referring to the more gender-neutral "teacher", that would be great. I can't think of any good examples off the top of my head. But it's pretty clear to me that the study is not well-designed.