It is possible the bone fragment washed up from another much further area. Recently there has been information in the news that debris from the tsunami in Japan has washed up on the western shores of the US and Canada -ranging from the San Diego area to the British Columbia area. Without the police report or coroners investigation report (not sure who would head up the investigation) to determine what, if anything else, was found, we really don't know and can't determine where this bone fragment may have originated. The coroners office will sometimes add personal effects found near the remains if they believe it will help lead to an identification. Sometimes personal items such as clothing, jewelry, or even coins/currency are added to NamUs and the other databases. No personal effects or items are listed with this particular NamUs case.
It could go either way. After sitting at Wrigley Field 5 outs away from going to the World Series and not going, I've learned to never to say it's gonna happen, until it happens.
Nothing other than DNA will give us the results....... Whatever the outcome.
The outcome has already been determined, we just don't know what it is yet.