Originally Posted by crazy banana

That is weird. My Blue Java usually fruits around 12'. And I am 100% sure that I have sent you a Blue Java.
I remember that you were saying that the plant/p-stem had some slight damage when you received it and you had staked it up somehow. Is that correct? Maybe it is related to that or like mentioned above, it is growing out of some kind of deficiency. Remarkable the growing rate from about 24" pup mid May this year in only 3 month to 5'. No mix up on your end?
I don't think it is a pre-flag leaf. Usually there is some bunching of the leaves at the top of the plant and you will also see some bulging where the inflorescence is about to come out. It is hard to tell by your photos, but my best guess is that you probably will have to wait for an inflorescence. No matter what, keep us all posted. Interesting case we can all learn from.