To be fair to the gnome, he's probably seconds away from throwing up and has a murderous headache from the massive amounts of blood flooding to his head. The discomfort he's experiencing when he demands you cut him down is probably terrible.
Then when you do cut him down he makes it clear he expects you to mistreat him anyway. The guy's just a cynic who's probably been abused most of his life. He's more cordial once he realizes you're NOT going to extort him for the rescue, but he seems too socially awkward to apologize and just offers his backpack as recompense.
I agree, Barcus, the gnome, becomes more open and friendly after you tell him, that you are not here to loot him. He even tells you, why he is on the road. I totally understand, why he is standoffish at first.
