Tough to see from the video but it could be any one of us that visit the mountain regularly, but if I was a betting man, I would take a shot at who I think it is.
I have made that hike many times as well and it is amazing.
Our Airpark is 30nm from the crater. Two of our residents, and my good friends, are RV6 and RV8 builders/fliers. They also happen to be geologist and Volcanologists, one being the leading expert in the world on the 1980 eruption. They are both real life characters portrayed in the book "Volcano Cowboys".
Hiking or flying the mountain with them is a geology lesson every time.
Smart People do Stupid things all the time. I know, I've seen me do'em.
RV6 - Builder/Flying
Fiat G.46 -(restoration in progress, if I have enough life left in me)
RV1 - Proud Pilot.