I can't do that. I can find the non randomness after the fact but not before. I see your point. Case closed. Sorry for wasting your time. Have a profitable trading.
Well, hang in there. Actually, what you are doing, is making sense of the chaos. That's a good thing.
Your example is evidenced by the obvious downtrend prior to the event occurring and highlights the fact that the people on the other side of their trade were not of equal intelligence of future market events, thus making the "coin toss" between these two participants skewed to the ones with prior knowledge. Efficient yes, random, no.