1) You can cancel a bounty you placed without refund. (The bounty office is under no obligation to correct the assumption that a bounty exists with hunters in the field)

2) A limited anonymity could reasonably come into play.
* Pay a premium to withhold your identity in the general bounty list
* Know that the office can be bribed to give up your name
- The larger the bounty the higher the bribe? Why stick your neck out against someone with that much copper?

Whether those sound good to the staff is one thing and whether they are worth doing is another. The first suggestion is something that has never crossed my mind, but the second.. I'd pay an extra 5-10% to get my name off the list. At the very least I know I'd be forcing someone to pay that much to find out who I am. }>