The IDF investigations into the events of last year's Gaza operation have identified a case where an IDF soldier seems to have killed two Palestinian women in criminal circumstances, i.e beyond what can be justified by the context of war. He will be charged according to the evidence, and tried; should the evidence suffice he'll be convicted. Which is as it should be. We're a democracy and live by the rule of law.
Does this bolster the credibility of the Goldstone Report? Of course not. On the contrary. The biggest lie of the many lies of that document was that Israel engaged in a purposeful policy of killing Palestinian civilians. If anything, this case proves the opposite. Another thesis of that report was that Israel, alone among all democracies, cannot investigate itself. This case seems to say the opposite.
(If you missed it but are interested, my reading of the Goldstone Report is here).