Let me rephrase my original comment. If the guys at the TradersExpo booth only used your rules of volume, their system could have bought as it was falling. Then when the volume settled, the system automatically sold lower. I took your scenario with no assumptions of other rules, including...
I've tried to get my mind around this as a working example and I'm not clear on a couple things. Since your rules do not utilize current price fluctuations, you could be buying as it's dropping, then selling as it settles lower. Would you provide a simple example of the entry, hold and exit...