There are guitar keys which have sharps and piano keys which have flats. When you get up into the high numbers of sharps and flats, you get a kind of crossover. Six sharps is F# Major, and six flats is G-flat Major, which are the same key. So this song could be in either six sharps or six flats.
With modern electronics, you can write and play the song in a simpler key like F Major (one flat) or G Major (one sharp) and have it come out in a different key. That may be what happened here. That octave leap at the end just sells it.
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