i was actually at this show. went to binghamton and pittsburgh to help my friend vent t-shirts. we actually know a pin vendor who spoke to the kid a few seconds before it happened. he said the kid never yelled "hike" or anything like that, but was acting rather oddly. he sprinted head-first into the window and dove right through. i was in the section near where it occurred and saw the broken window. pretty intense.
fwiw, the second set was the best furthur set i've seen yet. definitely emotionally charged.