The problem is that the Goldstone report was not initiated and produced in good faith. It was a political initiative, not a human rights initiative. That is the reason Israel should reject it. Because if Israel cooperates, a Pandoras box would open and the before you know it, Israel is expected to investigate organ harvesting allegations and other politically motivated allegations against Israel.
Ex-FM Lieberman: Firebomb attack in Jerusalem a reminder that norm is Arab terror against Jews (Haar
from the article: U.S. House backs resolution to condemn Goldstone Gaza report