Was this the intention behind the talent? It seems really over powered in my opinion. Even if the pick pockets roll is low, the theft still occurs (ie. the thief is in possession of the item they are trying to steal) and the only recourse for the victim and any other witnesses is to roll Perception just to notice that the theft has occurred. A successful Perception test does not prevent or hinder the theft from happening, it just alerts them to the fact that it just occurred a moment before.The adept makes a Picking Pockets test, the result being the Difficulty Number for attempts made to notice the theft.
Anyone able to observe the adept’s action, including the target character, may make a Perception test to notice the action immediately after the act has occurred.
How do other people handle this? Do you use the rule as written? Do you assign a target number for the Picking Pockets attempt and failure means they don't gain possession of the item?
I suppose an alternative (and maybe more in spirit with the rule) is the thief's roll is the difficulty number to notice the attempt. If an observer rolls equal to or higher than the Picking Pockets test, they can take one action before the thief completes the lift of the item.