Well if someone from the perceived establishment presents an analysis saying the establishment's thinking is flawed, wouldn't their own analysis be questionable, given they are a part of the group they are claiming has flawed thinking?
But stated differently, the flaw becomes apparent: "No member of any group can ever say that the group consensus is wrong, because they are a member of the group." But the one criticizing isn't a member of the group who shares the consensus, and the contradiction evaporates.