Well, the matter simply isn't clear... Here's a quote:-
It implies the bounty will go dormant if your ship is destroyed (bounty not claimed).
The above quote states nothing about it disappearing by itself (which makes sense but what is JManis talking about then?), and even more strangely, not simply paying it off (yourself)!?!
Oh - right, just a sec. You're talking about dormant bounties, which isn't an active bounty. There's an important distinction.
So a bounty, active or dormant, when
removed should become a legacy fine. So basically, that just means even when bounties disappear, they remain for you to pay to the relevant jurisdiction (or they'll forcibly be taken from you if you ever have to rebuy in their jurisdiction). There's no limit on the legacy fines, so you can run up gigantic legacy fines and then try to avoid being blown up in the fine-issuing jurisdictions' space if you don't want to be forced to pay them.
If you follow the dev posts in the crime thread (click on the orange elite symbol in the top right of each dev post to go to the next dev post in the thread) they do clarify a lot. It's a bit of a long haul to read so I'll try to get the relevant bits here:
An active bounty is one that is ticking down 7 days. It means the jurisdiction who issued it believe that you (the criminal) are alive, and they will pay their bounty to anyone who scans you to realise the bounty is there so they can bring a bounty claim voucher to the jurisdiction who issues it. However, when you blow up, you will also have a legacy fine of equal value to the bounty, and if you ever blow up in that jurisdiction again, they'll take that money from you during rebuy of your ship. The fine never goes away, unless you pay it.
A dormant bounty is what happens if you are blown up by some other authority, or by someone who isn't aware of the bounty from that jurisdiction. At that point, the jurisdiction believe you're dead after receiving news your ship blew up. The bounty becomes dormant.
If you're detected committing any kind of crime in that jurisdiction, they go 'WAIT A MINUTE YOURE NOT DEAD' and promptly make the bounty ACTIVE again and reset the timer to 7 days.
If an authority vessel of that jurisdiction scan you (and only them) while you have a dormant bounty, the same thing happens.
If a dormant bounty isn't reactivated within 7 days, it is removed, which means it becomes a legacy fine, just like in the other cases.
But in either case, if any bounty, dormant or active, gets to the end of the 7 days period, it WILL turn into a legacy fine that may come back to bite you later.
That's what the dev's have said, in any case.
So in my quote - the important part to note is "Note that when
a bounty is removed, for whatever reason..." Any bounty that is, of any kind. You will always get stuck with a legacy fine, or should do.