The Goldstone report does also cite the IDF report and it also cites Israeli leaders and Israeli citizens. It also used this newspaper. Apart from that their is physical evidence. From reading the report (and I was not counting) the single most important document "a charge" and "a decharge" was the IDF report. The main difference between the Goldstone report and the IDF report is not what happened but more the reasons, the details and the applicable rule of law.
from the article: Netanyahu vows never to let Israelis be tried for war crimes