That's how the law works - statutes are the final word until an appeals court (eventually the highest appeals court) agrees, adds nuance, or overturns them. In the absence of an appellate court ruling, the statute applies.
And given that my entire point is that a appeals court would overturn any murder verdict, I fail to see how the onus isn't on you to prove it. You're attempting to claim that my opinion is incorrect, you can only do that by providing facts contrary to that opinion. So the onus is on you to prove that such a conviction has
1) Ever been secured.
2) Survived an appeal.
You are failing to understand how the legal process works, apparently.
When a statute is written by legislators, the written meaning of that statute becomes law. The only means the written meaning of that law can change is by:
1. An amendment by the legislative body.
2. A court interpretation of the law that clarifies ambiguities open to interpretation.
3. A court rejection of the law based on constitutional or common law grounds where the statute, as written, violates codified legal rights.
In the absence of an appellate court decision that applies points 2 or 3, the statute stands precisely as written.
Now, if you want to assert that the statute does not stand as written and a conviction would not survive an appeal, you are the one making the claim that is unsubstantiated in law. That means that you have an obligation to back up your assertion by finding an appellate decision that substantiates your point.
Under no circumstances do I have to prove there isn't one (not to mention the silliness to trying to tell me to disprove the existence of something that may not exist). If a defense attorney or an accused wanted to argue the application is invalid, they would have to do exactly what you have to do - prove the statute as written is invalid.
If your point is that a court would overturn the verdict, as you've stated (with no grounds other than a mistaken interpretation of "spirit" and "letter" - for that argument to apply, one would have to show that legislators did not intend for first-degree murder convictions to result in this case, which would require a statement of intent in the legislation itself), the obligation is on you to show the grounds under which it would do so. You are pulling a luis and making claims about how a process works without backing it up. I have nothing to back up in this scenario - the statute applies unless a person challenging i (i.e. you) can prove it doesn't.
EDIT: And no, I am not spending my time researching appellate decisions for you. If you want to assert this would not survive an appeal, the onus is on you to show why that is the case - this is how Common Law systems work. I look forward to seeing the evidence used to back up your claims thus far in this thread.
EDIT2: And while I remember, so long as a statute is codified in law, it is not necessary to show a conviction has ever been secured under it to prove it valid. If a law is on the books and has not been amended, repealed, or interpreted by case law, it can be used as a valid charge without any sort of precedent whatsoever. So no, I don't have to prove a conviction has been secured, either.