henra,
"They (engine cowls) are torn on the bottom."
Looking at a slightly magnified view of that photo, all edge surfaces appear 'torn' (top/bottom fuselage, fin) due to photo resolution / enlargement.
As per Capt McHale, extrapolating the cowl marks rearward, suggest that there should also be rear fuselage / tail damage.
whereas oil stains … follow the airflow …