just last year I was faced with a deer walking away. I glassed him from about 1000 yards and thought he was a monster! walking away. I did not spend much time behind the spotter, just enough to know he was big and I needed to get closer. I ran down the hill and came up on him at about 300 yards. now I got a better look from head on and sideways. this deer was very nice, but not the 200 inch I first thought when I saw him in the spotter.
I relocated 80 yards above him and watched him bed, and continued to further judge him at about 180. he was a very respectable deer, and if you didn't comb over him with a fine toothed comb you wouldn't have known he wouldn't score much over 180. he only had 19 inch beams but the way his g2 went up right close to his base it really shrunk his beams, but when you saw him from the side you would have thought 23-24 inch beams. I had picked up his sheds so I knew not to get trigger happy as this wasn't the deer I wanted. just goes to show you need to spend a lot of time field judging to learn what big deer look like. if I would have went by him walking away I would have shot a great deer, but not the deer I wanted.