There’s blood pretty far up that thing, think about that sticking in his shoulder even for a moment, seems like it would be thru bone and into some important shit no matter the angle. And if his leg wasn't working, there must be a big ass hole in that shoulder. Seems like the broadhead got just deep enough to where it needed to go, probably not in the opposite shoulder but enough. Don't be discouraged of you don't find good blood. The whole could be plugged with the broadhead or bone fragments, fat or hide. Most of us have shoulder hit deer, the one that lived from mine, his shoulder was working just fine as he ran off. I think that three blade was in there doing work and he may have needed a few hours. Search far and wide today. Not blowing smoke, but on what you described I think he’s toast. JMHO.