So these bulls were being whipped to force them to break through some rubble.  I helped them kill their oppressors.  I am a gnome and all the gnome bodies, executed bodies, meant I had no love for the Druegar anyway.
They thanked me and made plans to vamoose, emphasis on the moose.  I looted a body...and they attacked me.  Apparently these animals are also guarding against theft from the bodies of their oppressors.
I don't think they were claiming the loot for themselves.
This is dumb.  Yes, I can come up with comedic reasons, too.  Fortunately it wasn't honor mode, so I didn't have to murder the ones I just saved.  Much like that stupid gnome in the escape cave with Sazza, who you rescue, heal him, then he wants to attack you.  I should just kill these entities.  I have a hard time believing it's designed gameplay.