Well if you really want to get down to it junkers aren't really unlawful. I mean they are to a degree but no junker would go and attack a hunter outright and nether should the reverse happen. So really in rp terms a bounty hunter could say that he had bribed those junkers to let him stay near their base, considering they aren't direct enemies.
But it is really oorp for those hunters to be killing the junkers right next to their base and for them to be docking on them. And sorry to say this Baltar but sig 13 has been like this for a while, and it won't be getting better anytime soon. New York in my opinion is alot better, hardly any cap ships around anymore with the new laws in place. You got the powertraders, oorp bounty hunter cap ships, and oorp pirate cap ships in sig 13. Just about everyone in that system is a little missed up(except maybe the GMG guys, they seemed alright in the few chances i ran across them).
And also why was a order battleship in sig 13? That to me seems worse than those hunters wasting a few junkers.