Your last 2 posts are the kind I enjoy reading. I also appreciate your determination to do it right.
I had almost the reverse situation several yrs ago. I had been watching & scoping a round grey spot and decided it was a stump. A while later I heard a little noise and looked, the STUMP walked out of sight.
In another area I watched a rather large spot that looked just like the side of a deer laying down. It definitely was NOT another person/animal. After 20-30 min. I remembered the stump walking off so.....
I aimed for the crease between the shoulder and ribs..BANG. ! Nothing.
I walked across a ravine and SPOT on I nailed a ROCK exactly where I aimed. DEAD rock.