And you think it always hits the same way? In fact the previous hit of a much smaller piece of foam did a gouge of almost 2 inches to the tiles and damaged quite a few tiles (the total depth of the tile). Considering that the video clearly shows the foam hit hard the underside of the wing, it would not be far fetched to think that possibly an even larger damage took place to the underside and possibly in a much more vulnerable area (like close to the wheel well).
"When fascism comes to America, it will be wrapped in the flag and carrying a cross." - Sinclair Lewis
"Those Who Would Sacrifice Liberty for Security Deserve Neither." -Benjamin Franklin