If you look at the photos in the article, the trusses are piggy-back. The top chord of the lower truss portion is not braced in any manner. The top chords are buckled out of plane substantially. By my estimations, we are only at about 8 to 10 psf of ground snow, even though it looks like quite a bit. This is roughly 1/2 or less of what the roof should have been designed for.