"International Standards"

The refrain about the Israeli probe of the Gaza flotilla incident is that it must conform to "international standards". And recently, I've been curious: What are "international standards"? Do they refer to anything specific? Or is it kind of like "international human rights standards", where "international" is deployed less for any substantive content, and more to piggyback on the fuzzy, cosmopolitan cadences of the word "international"?

Everything I've seen of international legal investigations, after all, tends to show they really don't have very high standards at all. Most war crimes tribunals, for example, are adjudged failures unless they secure convictions of high-ranking accused parties -- the "standard" is "guilty until proven guilty". There aren't particularly strong rule of law norms at the international level, there isn't a deep basis of precedent which acts as constraints against politicization, and there isn't a broad-based acceptance of the legitimacy of the international bodies to act as adjudicators. It makes the particular choice of rhetoric very, very interesting to me.