The arching of the back definitely says it all. I find that most of the time when i hit a deer they will jump and arch their back and thats with a rifle but with a bow i find they just arch their back and take off. The first time i shot at a deer with my grandpas old 30.30 no scope i shot at it and it jumped and arched its back and all i did was give its belly a hair cut. So if in the mornin if you dont find an arrow right where you took the first shot you should have nailed him.