its due to the smooth cut scar made on the alien example if a pain of class hit u at a str8 down angle it would tear u intwo and both parts of ur body will slide to the floor if a net gets wrapped around u and tightens the pressure from the outta skin not being hit burst with blood pressure casue the blood to spit so when scar hit that alien it was stra8 cut down the face once the alien hit the floor the blood would slowly start to come out