What Makes A Person Pale With Purplish Blue Skin Around His Ears?

HI I have a serious question. I just retired from the military last month and moved to Nashville. I've seen casualities, both U.S. and civilian. My wife and I were driving from our subdivision and we somebody laying in the yard in front of a push mower. We stopped I said "sir, you allright?" and I didn't get any response... I walked up and saw the man was older, looked very pale with purplish blue around his ears...long story short, activated ambulance, performed CPR...but he didn't make it...I have some very serious questions can somebodey help me?