Back in the earlyy 90's I was at a seminar on Exotic animals where Veterinarian from A&M Vet School there doing a necropsy to show how to do one and what to look for. He said that they would get a lot of animals in to run tests on to see what had they died from. He said that an antlered animal can poke into vitals and not break the skin. He demonstrated with a fillet knife show how it could happen. He said especially can happen on the rib cage where they lacerate the skin in between the ribs and then into the lungs never breaking the skin. Hard to describe on here but was interesting watching him demonstrate it during the necropsy. IIRC it was Dr. Mick Robinson (sp?) doing the necropsy that day at the seminar.