I have had a couple personal experiences.
A forky Buck following a Doe in Northern Ws. came by my stand. She stopped & I put an arrow through him at 20 yards. He stood there pawing the ground by her, stood a min. & dropped over dead. I ran her off when I walked up to him. Another time my brother & I spotted two Does as we drove through the lane to our tree stands in Ill.. I got out of the truck & snuck back 100 yards to where they were feeding at 20 yards. I shot & the arrow went OVER the Biggest Does Back & the arrow went into a corn field without making any noise.They kept feeding,I got another arrow ready & put it through BOTH lungs of the larger Doe-"SHE NEVER LIFTED HER HEAD" walked 5 or so yards & fell dead apparently never knowing she was shot-the other Doe stood by her until I stood up & then she ran.
This has also happened to two close friends of mine-they said there was no reaction from the Deer that they knew they had been shot. This was the Buck.