Fracture base of the skull should be suspected if there is ecchymosis of the upper and lower eye lids (raccoon eye), ecchymosis around mastoid process and/or bleeding from ears and nostrils.
One should also suspect a basal fracture when a concrete block was found on top of the skull being examined. Look at the fingernail on that one pathologist! Such personal grooming is as inappropriate for serious professionals as would be a Mohawk haircut.