The window material appears to be flexible—some kind of relatively thin security material, probably polycarbonate—not glass. Difficult to break, takes real effort. Does not form shards. No need to remove for “safety.”
Its safety glass. Very resistant to breaking, because a sticky center holds it together. It’s not flexible; it’s been shattered already, and I thought what he’s handling is mainly the sticky center, and that he was removing it to clear the shards from around the edges. But then it becomes quite obvious that he’s trying to create a nice clear passage through the window.