I don't think Goldstone didn't know he is investigating "crimes" typical for any war. I don't think Goldstone didn't know that IDF took all possible actions to minimize collateral damage to civilian population like no other army in the world. But... he has to do his job for his masters, no offence.
U.S. defense contractor accused of copying secret military documents (Reuters)
from the article: Dershowitz: Goldstone is a traitor to the Jewish people