Yep, I lost a fallow doe a couple of nights ago.
I was wandering into a high seat and saw 10-12 fallow in the corner of a field just below the seat. The wind was light but in the wrong direction and they winded me but couldn't quite place me and wandered across the edge of the wood in front of me. I was prone and comfortable and head shot a doe at about 40 yards. Solid bullet strike and she dropped on the spot. The rest of the herd trotted off into the middle of the field and I had the crosshairs on another for a chest shot at about 100 yds. Wasn't quite comfortable with the shot, as there was grass and the odd branch nearby so let them go. Gave it a few minutes and stood up, to find the doe looking at me through some thick grass - couldn't believe it was the same one - no obvious sign of injury, but she was the only one who didn't run off with the rest of the herd so took a second shot, despite the grass/branches and she ran.
Large pool of blood where she had dropped, various bone splinters and then my heart sank - a large, shattered mollar tooth. Picked up a good blood trail, and then perfect - it starts to piss it down before I've tracked it 30yards. I've had the dogs over the ground and spent hours combing a thick plantation where I think she headed but no luck.
The only small consolation is that there was so much blood where she initially dropped that she won't have lasted long. I've also been back to the spot I took the shot from, and looks like there was a couple of thin branches in the likely path of the bullet, which could potentially have caused a deflection. I've zeroed the rifle and bang on.
Anyway, bound to degenerate into the pitfalls of head shots, but it was the only shot on, and considering the circumstances I was more than comfortable taking it. I'd do the same again tomorrow (albeit, being a bit more careful for the odd stray branch).
I've been over and over what I did, and am happy I did everything I should and could have, but still a horrible feeling.