You are in enemy territory. After having previously shot a sniper and not being noticed, you see the next one ahead. Your commander is explaining what must be done and you know the sniper must die. You shoot the sniper while he is saying this. Everyone is alerted. You fail.
Starting over, you wait until the game adds "Shoot the sniper" to your objectives. You then shoot the sniper. Stealthy kill is successfully completed. This is Homefront.
This is what I hate about modern video games.