Kelly
I thought of that same video. One of the scariest things I've ever seen. No limbs and (I estimated 14-15 feet retic) that snake flew up that tree.
The explanation I had heard was that it was in pursuit of a monkey. I felt that was wrong. Definitely looked more like a retreat than aggression.
Adult Rocks are fairly arboreal also but of the 4 giants I think retics are the most athletic.D.C.