The Chasam Sofer in Toras Mishe explains Adam’s justification differently. The Midrash says that he drank grape juice. He was forbidden grapes but juice might be allowed. She was not commanded, so maybe she was allowed to eat the grapes and that is why she did not die but she also was part of him as the juice is part of the grqpes. So memanefshech, in either way he was allowed to eat. Why did she not die after eating? If she is part of him, she should have died and if she is not considered part of him, then I only drank grape juice which is not part of the grapes and therefore, in either way, I can contimue on eating.
Menu