If the airlines paid for a study, it would do nothing to sway the nutters, as they would be claiming biased results etc.
Why should anyone bother or spend $$ to shut up a small group of freakish nutters. Besides any study done will just be called another cover up....
Considering that I'm a student at a research institute about to invest significant effort into researching the impacts and management of CSG in Australia, I think we're in a similar boat (just with a bigger and more diverse "opposition").
Industry sponsors a lot of our research; yes we do get accused of lack of independence, but notwithstanding "you can only take our word", the industry doesn't just pay us out for results they like (they can pay an consulting company to do that if they want to
). Mind you, this is good and bad; latter because now the government, in trying to save more money, is very strongly pushing institutions in passive-aggressive ways to consider alternatives to Australian Research Council and other government grants, e.g. philanthropy or industry. So even less research in the future is deemed "independent".... but in the end it really is just about ethics - like doctors not trying to push drugs where drug companies possibly pay them a cut if they prescribe certain amounts...
However, I'm tempted to agree with both of you - just can't do the right thing by the wrong people. They are trying to exact a confession from people who can't do that simply because it doesn't exist*.
That said, if they are spraying, like QF63/64, then there's still a lot of people in Sydney under flight paths who are very much alive and not worse for wear!
* Happy to retract that in the future if we have a Lance Armstrong like scenario