Pheasants really don't go vertical.
They won't get up more than head high, or right level with the cornfield.
Either the hunters weren't staying in line as they worked the field or this guy just wasn't paying attention to where the other hunters were.
It was two separate groups, who apparently came upon each other with a brush line between them.
Depends on the terrain. I've seen them tower up pretty high, at least as high as over the nearest hill. I've also seen them misjudge that, and have to beat up a bit higher as they approached that hill, and then set their wings and glide a half mile or more down into the next valley.