This logical fallacy is especially dangerous for pre-modern Burmese history, at least for the pre-Konbaung period, not well-endowed with primary sources. Finding shortcomings in these sources and in the ways they've been used by previous generations of historians, even colonial historians, is easy; finding positive evidence that supports indigenous sources is much more difficult. A devotion to fault-finding instead of attempting to write accurate history, no matter how hard this might be to do, is likely to bring the field of pre-modern Burmese history to a grinding halt as everyone lays waste to each other's research projects. The purely negative can easily degenerate into a McCarthy era-like witch-hunt.
Indigenous primary sources have a literary quality that make them difficult to use in traditional factual narrative history. Professor Lieberman has partially vindicated indigenous sources by demonstrating that parts of the Burmese chronicle (U Kala's Mahayazawingyi) for which there are independent European sources are accurate (Lieberman, Victor B. "How Reliable is U Kala’s Burmese Chronicle? Some New Comparisons." Journal of Southeast Asian Studies 17.2 (September, 1986): 236-255).
Independent European or Chinese sources to support indigenous sources are not available for all historical periods. The narrative thread of the Burmese Chronicle begins with the creation of the universe and ends in the early eighteenth century which makes for a historiographical tradition radically different from the western Rankean tradition. Historical interpretations that must be based on this single source are likely to be uncertain and tentative. This is a problem also faced in many non-western historiographies, from American Indian "ethnohistory" to the interpretations of ancient Greece history found in the works of M.I. Finley like "The World of Odysseus" (which I am currently reading).
The problem lies in historical method. Showing that historical facts from the chronicle tradition are only weakly supported by sources does not provide evidence of the exact opposite facts. According to the pulitzer prize winning historian David Hackett Fischer:
"The fallacy of negative proof is an attempt to sustain a factual proposition merely by negative evidence. It occurs whenever a historian declares that "there is no evidence that X is the case," and then proceeds to affirm or assume that not-X is the case. He may have spent all his youth in the Antiquarian Society, feverishly seeking the holy X and never finding it. He may have examined every relevant scrap of evidence in every remote repository, without reward. He and every other reasoning being on this planet may know in their bones that not-X is the case. But a simple statement that "there is no evidence of X" means precisely what it says -- no evidence. The only correct empirical procedure is to find affirmative evidence of not-X -- which is often difficult, but never in my experience impossible...A good many scholars would prefer not to know that some things exist. But not knowing that a thing exists is different from knowing that it does not exist. The former is never sound proof of the latter. Not knowing that something exists is simply not knowing. One thinks of Alice and the White Knight:
"I see nobody on the road," said Alice.
"I only wish I had such eyes,"
the king remarked in a fretful tone.
"To able [sic] to see Nobody! And at that distance too!"
Spending a lot of time looking for negative evidence to disprove interpretation X can distract one from find the positive evidence that is necessary to prove what one really wants to prove, i.e. not-X. The "Fallacist's Fallacy" or "Argumentum ad Logicam" is pertinent here:
"Like anything else, the concept of logical fallacy can be misunderstood and misused, and can even become a source of fallacious reasoning. To say that an argument is fallacious is to claim that there is no sufficiently strong logical connection between the premises and the conclusion. This says nothing about the truth-value of the conclusion, so it is unwarranted to conclude that a proposition is false simply because some argument for it is fallacious" (Source: The Fallacy Files).
In conclusion, I would argue for a more positive and constructive search for better evidence. This evidence can be used to construct both: 1. fact-based Rankean histories, politico-military and socio-cultural, as well as 2. intellectual history into the historical discourses used in indigenous historical texts. Pre-modern indigenous historical texts are better viewed as speech acts in the sense of Searle, intimately involved in the making of history, often going through radical revisions with this use in mind.
[Note: Recently found an extensive review of Fischer's "Historian's Fallacies".