oh man tough break!, technically speaking the call was mine to give you something.. I used pickpocket as a way to keep it random. Sorry mate you got a sucky item there in your inventory. (you have a point though, maybe the Gobbo thing is a bit tough, still looking back over the rules It's pretty well implied you need to be careful...might change for future IBT to make optional pickup if you want...)
Still there are many aspects to the game...for instance gobbo could attack again at any moment and you might get a +3 to dice rolls (neutralizing your negative item - or making it worse). Also to note a dagger with +1 is currently available for purchase at the shop for a trophy..you sure had bad luck, but now you need to prove your the champ by working around it - if anyone can come back from this you can..good luck :)