The legal principle you invoked is the same. An act (pulling the trigger) in furtherance of a crime (murder).
You sure can. Try telling a judge you should get off scott free because you thought you were firing at some blacks but it turned out they weren't blacks after all.
You're going down for first degree murder (or attempted if you failed to kill) because your crime was premeditated even though you had wrong intel on the nature of your target.
You remain dishonest.
In a war, the underlying act, firing your weapons, is not illegal. In civilian life, people who are murdered are not separated into classes, with one exception. It doesn't matter who your murder as long as they are human.
But for sentencing, it can matter, such as killing a police officer or jail guard.
The better analogy is the one I used before but you refuse to deal with.
It is more akin to stat rape. If you think the person you are having sex with is under age and they are not, there is no crime.
But you admit you have no formal legal training right? You're just blowing smoke after watching a few episodes of Law and Order.
How many trials have you conducted again?