I'm no doctor and I don't play one on TV, but I look at the size of these wounds and wonder if perhaps the trauma is so great that it just shuts them down.
If you think about it, a heavy arrow may well knock the wind out of them and the size of the wound may put them in shock and somehow breathing is just shut down?
I don't even know if that is medically possible...
Regardless I'm glad you guys were able to recover your deer before the coyotes got first dibs.
I'm going to email this thread to a hunting bud who has been an ER nurse in Chicago for 20 years (means he has seen it all) and get his thoughts. I'll check back in with what his thoughts are.