No one knows. These guys are a big mystery.
Perhaps the OP can share some information on his standings with Guristas and whether the NPCs tried to point him or not. The kill mail does confirm he was on the undock, so I don’t know why he just didn’t dock up (or warp away) unless he was AFK, but maybe they web and/or pointed him. A frigate, or even bunch of frigates must take an awfully long time to chew through a tanked Orca.
A previous report suggest they don’t tackle you but that needs to be confirmed.
My guess is right now is that they don’t and you will be safe as long as you pay attention and warp away when they show up. But more information is needed.