This isn't about the PC dieing, but rather an odd way for a dragon to cop it.
I was at the dragon perch northwest of Shor's Stone, the one you have to climb through a mine to get to, and stealthily shot the dragon dozing on top of the word wall. He flew up and around so I thought to get the word while he was trying to find a good landing spot on that tiny area. I got the word and then heard the "whumph" of a dragon crash-landing. If you've seen those, they usually skid to a stop, plowing up the ground. I turned to see the ground churning from a point near the cliff edge right past the word wall, but the dragon wasn't there. Then I heard the dragon making a kind of disappointed noise, but where was he? The red dot was gone. So I went to the edge of the cliff where the furrow began and peeked over the edge. There was his corpse, half way down the mountain! He must've brained himself and fell to his death. I also found a rabbit and a fox stuck to the nearly vertical terrain when I got down there myself.
It was actually already dead before it hit the cliff.
Normally, if you one-shot something it drops on the spot; perched Dragons, however, are scripted to take off if attacked, so the death animation gets pushed back in the queue so that the script can fire properly. it
is dead, though, so after it circles back towards the attacker as per the response script, the crash-land death animation kicks in and it tears up the landscape upon impact. The physics thereof are a bit wonky when a hillside or cliff is involved, and in this case caused the corpse to zip past the edge and plummet down the cliff.