Oh, from what I read I guess goblin guards don't normally attack people over in PvE. I started playing in a Pvp server, if someone is attacked in a steamwheedle city the guaards jump the attacker, net him and most probably beat him to death.
Which reminds me of 2 little anecdotes:
I had come to Tanaris for the first time with my 46 lock and was out to do the water pouch bounty quest and killing wastewanders and such, as soon as I get there I see a dwarven 46 Pally battling a shadowmage and her voidwalker, the pally was getting a bit damaged by the shadowmage and I could've ganked him, but I decided to play cool since I was gonna be questing around the same area and didn't want nasty surprises, so I bowed at him and strode off a bit further to start killing my own shadowmage.
I don't trust alliance easily so I had my camera turned towards his direction and could see how he came in my direction from afar, and kept coming... so much for good manners, I finished both Shadowmage and Voidwalker and even tho I had to sacc my own pet I managed to kill him off.
Then I settled down to create a healthstone (tended to forget to create one before leaving town, that's corrected now) and rest and I soon saw his corpse disappear and well... since he had been such an ******* I guessed he deserved some punishment so even tho I had no pet and wasn't full rested I whipped his *** again at the loss of my healthstone. By the time he came back the 3rd time I was fully rested and had another voidwalker out, he still seemed to want to take me on I had wasted neough time so I gestured /no and /rude and galloped off to the other side of the field where he didn't come to bother me again.
He deserved the beating for wishing harm upon a courteous undead lady :P
P.D: Funny thing, all throughout the fight I was so into it I didn't recall or notice my soulstored icon on me the whole time, so the stupid bugger didn't stand a chance really and I had been worrying for nothing xD