Wow -- glad I've never seen that in person -- You say you saw the whole clip, did the turbulence behind the aricraft throw them at all?
I was once part of a 4-way jumping out of a Porter following a couple of solo jumpers when one of them decided to open at 6500' without any waveoff. The bastard almost giftwrapped all 4 of us. As I flew by, I felt like I was close enough to punch him in the face. Fortunately nobody was hurt, and wise people on the ground walked us away long before he ever got down and others sent him home (banned from the DZ) while we were packing.
--Sky