I shot a doe last night. Hit her perfect. Dropped dead after a 60 yard sprint not 30 seconds after I stuck her. Double lung. Chalk up another for the Muzzy.
The blood on the arrow and the sign where the deer was standing, as well as how the deer acts after you stick it, and any noise the arrow might make on impact can tell you a lot. If you stuck a deer behind the shoulder, and know you did, then that deer will die within 200 yards. You will have pink frothy blood, spraying up to 5-6 feet on either side of the trail the deer took, and it will be full of bubbles. The spraying is why people often think that lung shot deer don't leave much of a blood trail. They do, just not where you might expect it. If you take out a deer's lungs, its done within a minute and a half. Conversely, I have been on the blood trail of many a friend's deer who claim to have double lunged it, only to find it a day later with an entrence and exit wound just in front of the hind quarters.
Only deer I have ever lost bow hunting I lost last year. Deer was damn near right under me, 7 yards from the tree. I put the pin right on its armpit and hit the release. Felt solid, sounded fine. Deer ran hard for about 100 yards, then stopped and blew and trotted off. Turns out I smacked her in the back of the front leg. No bone, just a muscle cut. Plenty of hair, and plenty of blood, that slowly dissapated into nothing but a drop here or there. The arrow looked like a pass through on the top and a miss on the bottom. Deer lived and was killed a week later out of the same tree (ironically by me). Big scar on the back of the left front leg.
A little tip from someone who tracks a hit deer about every week or so: If the deer crosses a log, road, field or path, these are all excellent places to pick up a lost trail, or better analyze what kind of shot you made. A deer hit quartering away behind the shoulder might only drop blood every other step or so because the shoulder blade will temporarily cover up the wound. And of course, when it doubt, get out. Always leave plenty of time for the animal to expire, especially on an iffy hit. Liver hits usually take between 15-30 minutes to kill a deer. Hearts are usually 45 seconds. Lungs about the same, but only if you get 'em both. If you hit the deer in only one lung, it can make it as long as 5-6 minutes, or longer. All depends.