I haven't played much Eve around fighting and standing. I have only been a miner. But i have been searching, and i found this site that explains what standing is.
eve grismar
But what i read, i believe that when you are -5 with the "faction", which sometimes mean "everyone that accompanies that faction", i'd think that it would be impossible to speak with anyone within that faction.
But to be able to speak with them again, and do their missions. You have to go and train Social skills, which increases the faction standing of every faction by x.
Maybe some other answer will help out more.