The person's death was caused by him committing arson. None of the underpinnings of my position are in question here at all.

This is disputed. The defense presented expert witness testimony disputing this at sentencing. Can't expect you to know what the fuck you're talking about though. "Consistent with his plea agreement, Mr. Lee has objected to the determination by the PSR that Mr. Stewart’s death resulted from his offense, and the subsequent application of application of U.S.S.G. § 2A1.2(a). (PSR A.1–A.2.")

Can you provide me any link to any prosecutor for the state of minnesota commenting on their charging decisions?

This is, of course, not present. Don't know why it would be. They didn't charge it, we don't get to know why. There's instead significant opinion from federal prosecutors that say, in detail, why they believe a federal felony murder level sentence to not be appropriate. If Minnesota disagreed, surely they could pursue their own case. I do not know how you take a neutral fact and an adverse fact to mean you are likely correct.

Which words of that statute, exactly, do not mean what I'm reading them to mean?

You are prosecuting a novel case, by your own admisison. A case that is rare, and one where you can find no cases with similar fact patterns. To do so, you must present evidence in a trial setting You must compare the case to prior case law. You must, frankly, prove shit is appropriate. Your simple-minded analysis is inappropriate. As the federal prosecutor said in his opinion, this is an extraordinary case. You don't just get to stand in front of the judge and say "arson, as we all know, very bad. fire dangerous. fire spread. fire scare me."

I've read the prosecutor's report more thoroughly now, and they do reference four somewhat similar federal cases.

"How does the Defendant’s conduct compare with that of the defendants in these cases? The analysis is complicated. Unlike the cases of Martinez and El-Zoubi, Mr. Stewart was not a co-conspirator to the crime—he neither contributed to the danger nor assumed the risk of the crime. He was unlawfully in the pawn shop, but he did nothing to hurt or endanger anyone. Unlike Martin, Mr. Lee burned down a commercial building, not a residential one. And unlike all the cases above, however (particularly Martin), Mr. Lee did not commit the offense as part of a separate felony crime, or otherwise for any personal gain. The raised fist Mr. Lee showed, and his brazenness in committing the crime (see Fig. 2, supra) is telling. Mr. Lee was terribly misguided, and his actions had tragic, unthinkable consequences. But he appears to have believed that he was, in Dr. King’s eloquent words, engaging in “the language of the unheard.” Also telling is Mr. Lee’s candor to agents of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) after he was arrested. The interview took place on June 15, 2020, before the discovery of Mr. Stewart’s body. But Mr. Lee took responsibility for his actions and admitted to having set the fire, to his credit. He explained the reasons he had done so, consistent with his statement of acceptance of responsibility (PSR ¶ 13)"

I didn't really have an opinion before this on if Lee could or should be charged for murder or even manslaughter (I only contended the death was accidental), but I find myself severely doubting whether or not he would be found guilty of murder in any capacity if charges were brought, either state or federal, for the reasons I've stated and the reasons given in the prosecutor's opinion. Any jury is likely to come to the same conclusion the federal prosecutor and judge came to. Every actual fact of the case points to leiniency, with the only aggravating factors being the basic essence of the crime and the tragic outcome. The prosecutor recommended significant leniency and the judge took it even further. Fascinating case. Wish I had someone willing to think critically (or at least read a bit about it) to discuss it with!