The rules for intelligent magic items use "owner" and "possessor" somewhat interchangeably. And, of course, in general the owner of a magic item is presumed to be the possessor. Magic items with high Egos are said to be able to take over their owners in one place, and in another place the rules for when such an item can dominate its possessor are detailed:
Intelligent items with high Ego scores are difficult to control and can sometimes take control of their owner, making them dangerous to possess.
When an item has an Ego of its own, it has a will of its own. The item is absolutely true to its alignment. If the character who possesses the item is not true to that alignment’s goals or the item’s special purpose, personality conflict—item against character—results. Similarly, any item with an Ego score of 20 or higher always considers itself superior to any character, and a personality conflict results if the possessor does not always agree with the item.
When a personality conflict occurs, the possessor must make a Will saving throw (DC = item’s Ego). If the possessor succeeds, she is dominant. If she fails, the item is dominant. Dominance lasts for 1 day or until a critical situation occurs (such as a major battle, a serious threat to either the item or the character, and so on). Should an item gain dominance, it resists the character’s desires and demands concessions […]
So the rules already lay out a way for an intelligent magic item to work for other aims (possibly including further the agenda of its creator or another party) against its possessor's aims, even if its possessor is its owner, and make no distinction between the item's current owner and any "true" owner it might claim to have.
What's more, there are some interesting rules quirks that would arise if the owner could be anyone besides the possessor. In particular, the ability to pull an NPC that might be hundreds of miles away into initiative is certainly quite impressive.
Possession does not need to be limited to touch, either; Paizo's blog added a specific intelligent magic item ability, Leaping:
As long as the possessor has the item on his person, as a free action he can call out to the item, causing it to jump into his hand (if that is how it is wielded) or equip itself in the appropriate slot (if it takes up a slot).