Wakeen, the guide is demonstrating tree-well dangers. He likes to visually demonstrate the danger. A tree like this is most likely 15-20' but with the snowapack only the top section of the tree is above the snow leaving the wider section to create a large cavernous pit. Wakeen is an expert (for real) in avalanches and all things snow...so he can do this! he just walsk up to the top side of a well (the most dangerous place) and jumps in. He extracates himself by climbing back up with the branches. If someone does fall in, never appaoch from the top/uphill, always to the backside/downhill side as you will just end up piling snow on the person. If you fall into a well, don't panic, move slowly, try to get to the center branches. if upside down, its much more difficult. try to get your skis off and right side up. This is why I ski this kind of terrain now with a Avalung. We learned a HUGE amount last week about BC safety. The one day when Avi danger and heavy snow precluded skiing, we did a whole training session on how to evaluate snowpack using pits and evaluating snow layers and the use of beacons. Its really interesting stuff.