I've been really fascinated by the Gracie Combat Punch Block Stages for the last year or so. So much so, that I incorporated it into my own self-defense curriculum. I had actually though they just went from Stage 1 to 4, so I'll have to do some research about Stage 5. By your description, it sounds like what I would call a "Crazy Legs" escape. Great stuff, @davidrichards, thanks for sharing!
RE: Musings from the BJJ Gi #4; Lesson 2