Perhaps there is not a "no man's land". There are however places that appear to be perfect shot placements that result in deer not recovered. I've seen it first hand, and anyone that cares to click on the link Joe posted can see it on video. It isn't theory, or an excuse. It happens, and when it happens to you, its nearly enough to remove all faith in archery tackle. I've never had a deer shot through the middle of the ribcage travel or live long. I can't say the same for deer shot in the triangle.
Deer are tough animals, some seem to be tougher than others and occasionally a few just defy what we know to be true.
Why some deer don't die from some the shot placements is open to a bunch of speculation and reasoning, some may have no plausible explanation. Others could maybe be rationalized and explained through angles, broad head performance, who knows.
Many years ago my nephew visited from Texas to bowhunt with me. He killed his first buck ever with a bow the first morning, he shot it in the back leg and it didn't make it 30 yds. I complimented him on being such a skilled bowhunter and bow shooter. He asked me why, I told him most bowhunters would just shoot the deer through that great big heart lung area, it takes a special skillset to kill a deer by shooting at the femoral artery.
While there can and seem to be exceptions to every rule as a general outcome you can't push a broad head through a deer in the chest cavity, below the spine, without it dying, and dying pretty quickly.
