If you're aiming at a specific location, you don't randomly determine hit location. Angle of attack then is moot.
If your shot connects, you strike what you were aiming for, regardless of angle.
You'll also note that when shooting normally from a 'Below' angle, it's still possible to hit the head, just much less likely. If you re-roll the location, and it resolves to 'Head', then the 'Head' result stands.
Likewise it's possible to hit the legs when the angle is 'Above'.
If your Aimed shot misses, it's considered to have missed the target completely.
Paul