I recently had an opportunity to critically evaluate another contractor's document. This contractor happened to be working for the entity legally responsible for a big mess. Critical evaluation is one of my favorite things, so I really dug into the document, catching everything from typos to major omissions and unsupported conclusions.
The site in question has a... boisterous group of environmental activists. When they got a look at our evaluation, they were ecstatic that they had someone "fighting the good fight" on the behalf of the environment.
Well, not really. I've worked on contracts for the "good guys" (regulators) and "the bad guys" (industry), in both cases working to figure out what's going on in the environment. I have a moral and legal (I could lose my license!) obligation to be thorough in my investigations, and to not misrepresent what I discover. But my reputation depends on my skills as a scientist, and not in twisting the facts to represent one agenda or another. I've never felt pressure to misrepresent the facts as I saw them, although maybe I've just been lucky so far.
As I explained a long time ago, I don't consider myself to be an environmental activist. I will admit it is still fun to poke righteous holes in other consultants' reports, though.