For the institute you have a situation where there's an institution regarded as objective and credible and someone who has a vested interest in the outcome donating money. This happens all the time. There's some form of regulatory capture in any industry, even if the regulation is something like "a general consensus among certain people that everyone in the industry respects that something is or isn't ok."

Like in government, sometimes there is quid pro quo and sometimes there isn't, but I've never heard anyone come out and say, "Whoops, you caught us! We're totally taking money to sway our opinion!"

The breadth of studies makes this look pretty legit. I just don't put much faith in obligatory denials.