By this doctrine they place themselves above God and the bible.
First example is something is true in the bible but not endorsed by the FDS:
If a JW finds something to be true in the bible, without a doubt in their mind, they can only believe it if it's endorsed by the FDS. Similarly, if the JW finds something the FDS teaches to not be in the bible then they are not allowed to reject the teaching. Here is a great example of this: My dad was the PO for most of my teen years and at one time he was the only elder in a cong of around one hundred. Well, one day we were talking about the disfellowshipment arrangement and why the people have to wait so long before they are reinstated. I thought that if a person was repentant that they would be reinstated immediately, so I posed a hypothetically question to my dad. If someone were repentant after one month or less of being disfellowshipped wouldn't they be reinstated? He said no!! and then said that he did not agree!!!!!! I about fell out. He proceeded to tell me that there were mandatory time limits placed on disfellowshipped ones and they could not return before they had reached those time limits. Then he explained that this was not a biblical teaching and could prove it! Nonetheless he had to enforce the FDS teachings over what he knew to be true in the bible. Both my dad was placing the authority of the FDS over the bible, simply because he would be seen as "running ahead".
Second example is something that is taught by the FDS but it is not found in the bible:
There is one slightly different way that a person can disagree with the society and still be running ahead. Say, that a JW in the Golden Age period found that the reasoning for not allowing vaccinations was not found in the bible. This JW would have to wait on the FDS to change their minds before they could receive vaccines; they in no way would be able to claim that they don’t want to follow something that is not in the bible.