I find it hard to understand the conflict of interest with government-backed science. Scientist A gets a grant to do research, spends it on research and reasonable salaries for PhD's, and goes on to join the EPA board. So what?
It only becomes a conflict of interest if they then start allocating funds to their friends or to themselves, but that's almost too obvious. What does them having previously received grants have to do with anything? Why would they then be more corruptable than private sector scientists?
At least in the case of government-backed science, the research goals are generally aligned with government interests. I don't see how that's sinister in the general case.
On the other hand, it seems much easier to find dark motives in research conducted by corporations. For instance, why would you publish research that is bad for your company?
What am I missing here?