Zingnut.. interesting information.. Like MLKeith said, high lung shots donot always bleed because it takes so long for the body cavity to fill before getting to the holes is what I was told. Whether that is true who knows. At least the critter did not get to far from the sound of it, since you saw him drop.
I shot one many years ago in about the same place you're describing. Never actually hit the heart but took the lungs out. That was with a roundball. I'll tell you, I looked for blood and sign, I almost thought I missed the deer. Unfortunately, where I hunt, if they run off 15 yards, you seldom see them anymore. I cut me a tracking stick and started tracking that rascal and finally got a smear of blood on a bush leaf. It was not much further then that and finally some blood was showing up on the bushes, not so much on the ground. The deer actually only made about 40-45 yards on me from the point of hit, but when they run into the thick stuff, they can disappear in a blink of an eye.
Glad you found it. Sure is a pretty buck. I also have been shooting the XTP's lately only because the rifle I was hunting with likes them or the Barnes Expanders. Barnes Expanders are over a $1.00 each. XTP's are cheap in comparison and shoot very well out to 100 yards for me.
Better luck next year with a giant one. Today, I had to run into town. A
monster 8 point crossed the road right in front of the old truck. Still had his rack and everything. He sure was a proud looking devil, figuring he made it through another season I guess...