One thing I forgot to mention about that chart...it appears that person was not requiring "equal weight" BBTs, right? Because BBT1 has a vol cycle while BBT2 does not. Ok. But, all three BBTs, as the final annotation of that chart, are complex. So, that's all I can come up with...maybe that tape couldn't be compete at what is now Pt2 because to that point BBT3 was not "complex"?
Although, requiring that aspect to be achieved doesn't make sense if we aren't requiring the BBTs to be equal in every way, since in this case they'd all need a full volume cycle.
So that brings me back to the original question. Is there ANY way to know the tape might not be complete at what is now marked as Pt2? Any clues? Or is it as simple as wilddog commented in that no method covers every base (he's correct on that note), and that is a reversal we'd be compelled to take. No other angle to see it from, I suppose. Just have to manage the trade and in this case the WMCN simply didn't materialize.