Haha, I had almost the exact same thing happen with a different Petty song (American Girl). I have been playing it for YEARS with the last two notes of the intro (the d to e right before "well she was an American girl...) one octave lower than the record just because it sounds cool live and fills up the stage. I do this with other tunes here and there too, especially if I have a fiver sound.
A few weeks ago our lead singer hits me with " why are you doing it differently, I can't find where to start singing!". I have literally been playing it this way for five years or so, but suddenly home boy can't feel eight and it's my fault![]()
For me, that's what a 5 string is good for. Toward the end of a song (if it fits) I will go an octave lower to make the song sound "bigger" and build to the end. Some get it. Some don't.