All of history is a judgment call, to a greater or lesser extent. Unless something was recorded immediately after it happened (and even then it is subject to the frailities of the human mind), all we are left with is imperfect records and assumptions. With which we make the best judgment we can of what may have happened.
At first my thought was "huh?" But, Monty runs deep - and indeed, history is the "agreed upon set of lies", sayeth some wag of the past.
That wag was Napoleon Bonaparte.
But to me, the nature of TIGHAR's quest is not to write probable history, but to go look for a lost airplane, find it if they can, conserve it if possible - and in the process end the mystery. That is my narrow view given what I understand of TIGHAR's role in this things as taken from her own charter. If we dabble toward 'conclusions' based on what we have now, we merely have 'the best idea of what happened, barring a better solution being found with as much evidence, such as it may be'.
"Probable history" is the only kind of history there is and "dabbling toward conclusions based on what we have now" is the best we can ever do. We always want more than we have now but at some point each of us says "That's enough to convince me." The debate comes down to how much is enough - and that is always an individual decision.
Look for a lost airplane? In all probability the airplane is gone. All we can do is look for whatever bits and pieces remain. How much will be enough? Do you need something that is unquestionably from a Lockheed 10 (until somebody questions whether it is really from a Lockheed 10) or do you need something with a serial number that can be matched to records of NR16020 (only the engines, prop hubs and prop blades had serial numbers that we know)? Does "preponderance of evidence" count for anything or, like my old friend and nemesis Tom Crouch at NASM, do you maintain that TIGHAR has found nothing of significance in discovering the fate of Amelia Earhart?
I look back on all that we have learned and discovered and recovered over the past 25 years and it seems to me that our biggest problem is not a lack of evidence but rather an over-abundance of evidence. To illustrate what I mean, answer this question: Why does TIGHAR think the Earhart flight ended on Gardner Island? If you're a dedicated TIGHAR you can probably list a half dozen pieces of evidence that support the hypothesis. If you're a skeptic you can probably list a half dozen pieces of evidence that you feel can be explained away. Either exercise is like dancing on the tip of an iceberg. What is needed is for the entire corpus of research and analysis to be pulled together and presented in a way that makes it accessible and easy to understand. That's my next book Finding Amelia - The Castaway of Gardner Island. Regardless of what more we find (or don't find) next summer, the story of what we've already found needs to be written.