Tunguska space rock – has it been verified?

At http://phys.org/print290254727.html … rock samples from Tunguska appear to be meteoric in origin according to a paper in Planetary and Space Science (5th June 2013) by researchers from the US, Germany, and the Ukraine. It is supposed, from this, that a meteor exploded in the atmosphere over Siberia in 1908 (much like the Feb 2013 Russian meteor – but presumably of greater magnitude, or lower altitude).