(Edit: The Seller went over to his post office yesterday and spoke with them, and they confirmed that this letter did in fact go to Hawaii for some strange reason. Thankfully he's been very patient and understanding throughout all of this.)
That is odd, because my last go around tracking saga, my local PO could only confirm that the tracking info I received is what they can see, not that it was actually correct.
They suggested that could only be achieved by directly contacting the facility, in your case, in Hawaii to confirm, which in my past experience trying to do on the phone, is nearly impossible, I suspect also by design.
You are fortunate your addressee is so accommodating, many are not.
