This is just a thought and in no way a gripe but, when I get interdicted I assess the ship that is attacking and then open fire as soon as so that I can get in the first shots. But..... not all the ships that interdict are wanted so by defending yourself you become wanted.
This seems unreasonable as if the NPC interdicts you he is committing an aggressive act surely?
Thoughts?
I think you were dealing with a Bounty Hunter, not a pirate. Bounty Hunters in 2.1 are using Kill Warrant scanners now, so if you have a bounty on you IN ANY system, they can interdict you somewhere else and try to take you out. Until they fire on your ship, they usually scan as CLEAN. If you fire the first shots after the interdiction, then yes, you will gain a WANTED rating on you. But... If you wait and let them take the first shot at you, then they will be wanted and THEN you can fire on them with impunity!
Just remember that if you have a dormant bounty in the system this takes place in, when the SA ships arrive and scan you, they will see that bounty and will reactivate it, and you will then be considered open game! The best advice I can give is to make sure you know your status in any system you are in at any time, so that you know what can happen in advance.
But back to the CLEAN interdictors.... These guys are bounty hunters, not pirates.