So I'm at a vendor yesterday and buy a few low-value potions, and when I tabbed the trade menu closed a series of messages appeared in the top left corner of the screen, something like:
Removed 125 gold
Removed 645 gold
Removed 325 gold
Removed 440 gold
I can't remember the exact message text, but it was something like that, and the total removed was over 1000 gold, when the potions I bought were only worth a couple of hundred.

Anyone else seen anything like that before? Can NPCs pick pockets?

*deleted* nevermind

Its because you purchased the potions from the vendor.

EDIT: I wish NPCs can pickpocket the player.

You're pretty funny. c:

If that's happen i wish to be able to kill the thief with no bounty added as everyone would do with me when i get caught pickpocketing.