I watched the movie Larry flagged here.

Maybe it's just me, but it looks an awful lot like something came out from under the wing, swirled forward in the turbulence, broke in two, and came back and hit the underside of the wing but good.

What if this object WAS a piece of tile, breaking loose at launch and being blown forward for a second before being fractured and thrown back against the underside of the wing? That puff of whatever at impact looks a lot more like something brittle was blown apart (like a tile) and not like a piece of foam hitting something.

Of course, I don't have earlier frames which may show the debris falling from a position further forward.

I don't know how far downrange the Shuttle was when this occurred, but a cursory search of the ocean surface below that point and downwind might not be a bad idea. Tile or foam--the fragments would float (unless it was a piece of ice).