You hit bone, that's why you didn't find the deer. He may even still be alive if the arrow didn't penetrate too far beyond the shoulder blade and into a lung. If you wouldn't have hit the shoulder blade, you would have more than likely taken only one lung and guts on a pass through shot. Good luck trying to find a one-lunger! Like the others have said, don't take this shot again, learning is a good thing.

Broadside or 1/4 away. Stick with that. JMO because that's what I do.