We don't know how hard Jesus was flogged (Pilate seems reluctant to kill him at all). We don't know that his feet were nailed to the cross. We don't know that the spear pierced his heart and lungs - it could just as easily have pierced his bladder, causing water and blood to come out. Pilate was surprised that he was dead. John 19:17 says he carried his own cross to Golgotha, so he clearly wasn't suffering from hypovolemic shock. You are misquoting the bible there.
