There was a rather large dicussion about "load bearing surfaces" and what being in the loading zone was defined as, in
this thread. The best solution to make sure that you are always in is anything that hangs off of your robot within the base, such as zipties. I didn't actually see a not-in-loading zone penalty at BAE in the matches that I watched, but I am fairly certain the Q & A in that thread is what they based their ruling on.