Are the people who wrote and signed it. Their methodology was flawed, testimonies and interviews that were public domain were ignored if they favored Israel, at least one of the Goldstone Commission members signed a public petition accusing Israel of "war crimes" during the operation. The bare facts that have come to light in the Hamas admission that the "policemen" were actually Hamas fighters and that over 800 of the "civilian" casualties were, in fact, Hamas fighters seems to have escaped you. Either that, or you already made up your mind and don't want to be confused by facts. The indiscriminate firing of unguided rockets and mortar shells at civilian establishments (towns, kibbutzim, moshavim) by Hamas, Islamic Jihad et al is a WAR CRIME. Hamas has rejected the report out of hand because it criticizes Hamas as well. Read the original Goldstone article in the Washington Post--wshat is in HaAretz is just a summary.
Israeli PM to Palestinian President Abbas: We must fight terror together (Haaretz)
from the article: Hamas: Goldstone retreat doesn't negate war crimes committed in Gaza