That cage in particular has more than enough room but in tighter spaces our t-step also proves useful. That said, it's hard to debate these finer points on a forum. If we were in class and studying this scenario, we would break it down and moment by moment analyze movements applying our Wing Chun principles and feeling it work. Then we would practice it. I'm confident there are many solutions to each of these scenarios, and I'll throw out there that an elbow may be one of them.
~ Alan
The point was to highlight the problem with the center guard itself so as to fix it, not just put a band-aid on it by running away or resorting to other emergency techniques.