A stab wound to the abdomen is rarely fatal unless he hit the vena cava, which would quickly bleed out and then death..
Forgot to add this about bleeding out. We had a patient in our hospital that was scheduled for surgery. He was on the ward and was calling his wife the night before surgery. He had an aortic arch anuresym needing repair. He sat down and told his wife he was not feeling well and died. The anuresym dissected completely and pumped most his blood into his chest cavity. It was painless.