That sucks that you can't find that Buck. I know the feeling. This is my first year of bow hunting, but during one of my first couple of years gun hunting I had a similar experience. I shot a 8pt and thought I got it pretty good, but was worried I had hit it too far back. I waited for a good 45 min - hour and before I started looking. As soon as I walked over the ridge the buck jumped up and ran off. I thought, "damm, I'll never see him again". Lucky for me he ran about 100yrds or so and dropped. The fact is, its a challenge. Some you win, some you lose. All we can do is improve our aim, or equipmeny and our technique. In the end it comes down to a lil bit of luck. You can have the prefect shot, but at the last second the wind kicks up or the deer flinches and your "perfect shot" its a little back or a little high and your tracking with you fingers crossed. I'd hate to have meat wasted or not to find a trophy, but sometimes it happens to the best of us. Good luck in the future and I hope you never have to go through that again.
I second what westtexducks said, it might be possible that someone stole the deer, especially if it was close to the road.