That reasoning doesn't always work. There are plenty of harmful bacteria in the body kept in check by their location. Case in point the bacteria in your intestines. Now if the location is compromised, say by a knife wound or gunshot wound, the bacteria are freed from their confines and the infectious bacteria proceed to spread into the abdominal cavity causing all kinds of problems. Of course there are other mitigating factors here as well. The biggest issue is of course to stop the bleeding and repair the damage. This is complicated, however, by the bacteria released. Per my original disclaimer I am no expert and am quickly getting in over my head here. Would appreciate some input from those in the know here. Either back me up or correct me.