Still --- if the Devil comes for you -- and it could easily be in the form of a Muslim, would you want to tell the Devil you've just joined his side right before he takes your life?
Ah, a "what if" question. One with a premise that I reject because I'd have to agree that He would not know what this man really believed before he died in your scenerio. Or do you seriously believe that the Almighty does not have the ability to know such things? Do you think he might be unaware of some things? I don't.
This man tricked the trickster. And maybe that was what the Lord wanted? Or maybe not? No matter, none of us know.
One thing is for certain. The false god Allah took no innocent life this time. I find nothing wrong with that.