This sounds more plausible than some of the other stories I’ve heard. It doesn’t seem to follow Occam’s Razor that a civilization would have the incredible technology to cross hundreds or thousands of light years’ worth of distance only to crash in our mundane back yard.
http://www.cnn.com/US/9712/31/radioactive.oatmeal/
http://en.wikipedia.org/wiki/Tuskegee_Syphilis_Study
http://en.wikipedia.org/wiki/Operation_Midnight_Climax
http://www.bethedream.net/Landry_files/Human_Radiation_Experiments.htm
http://www.apfn.org/apfn/experiment.htm
and on and on— using Progeria sufferers for high-altitude experiments is unbelieveable because... uh.. why?