RE: Check out this picture...
If you view the photo larger, you can see blood coming down from the opposite "arm pit". The arrow must have punctured through the other side.
I know a photo like this will cause some controvesy. So before someone cries "photoshop!", let me say transparent photos are very common with trail cameras. As someone who's work requires the use of photoshop on a daily basis, I believe this photo is authentic. I won't bore you with the details of why I believe this. I'm sure someone will not read the whole thread and cry photoshop anyway.