As I recall from my reading of Torah, Jewish legal values are very specific about how testimony is to be regarded. Making statements without proof cannot be taken as the truth by the judges. Since the Goldstone report was mostly based on statements by Arabs (anyone recall the Jenin massacre story?) without any proof, it should not have given so much weight to those statements.
Defense Ministry says had no knowledge of alleged improper defense deals by Gal Hirsch (Haaretz)
from the article: Goldstone to attend grandson's bar mitzvah as Zionist groups end feud