The kill shot?

What the hell happened there? Like seriously, what happened? All we could see was the deer. The deer was standing up and moving. Deer aren't big animals that you can't see around them from a distance. The kid was big enough you would think he could be seen. But you don't see him until after the shot was fired. And the deer just seems to disappear. The kid it looked or as it turned out was standing right behind the deer. This just doesn't seem to make any sense. The kid was also wearing bright clothes. The deer no doubt would have known the kid was near, but seemed oblivious. I live where there's lots of deer and know what their senses are like. You can't get that close to a wild deer and as soon as you do, the deer begins acting skittish and watches you closely. So alas this brings me to ask, what are we suppose to believe as to how this went down?