First of all, I agree with some others- given the steep angle of the shot, the hit looks to be too low. Second, I also agree that 1 lung-shot deer can live for a long time, or even survive the hit completely.

In my experience, only a double-lung hit, heart shot or hit on a major artery will anchor a deer quickly 100% of the time. I've recovered 1-lunged deer, but I've also watched a fair share of them run off, never to be seen again.

One hunting experience of mine really enforced by belief that 1 lung hits aren't lethal 100% of the time. 2 years ago,a bowhunter hit a huge 12-pointer that ran off onto our property. He came and talked to us and asked us to keep an eye out for it. Later, during gun season (about 6 weeks later) a gun hunter shot that buck. The original bowhunter identified it as the same deer, and the part of the arrow was found lodged in its chest- in 1 lung, but not the other. No other vital organs or major arteries were hit. The archer thought it looked like a perfect hit, but because the angle of the shot, it barely missed the second lung. After 6 weeks, the deer had lost some weight and didn't look 100% healthy, but was still alive.

Just because you shoot a deer through the chest, it doesn't always mean that you're going to find the deer dead 50 yards away. Deer are very tough animals, and the only way to be sure 100% of the time of anchoring a deer is putting a good, sharp, broadhead through BOTH lungs, the heart or a major artery.