I would never take legal advice from a debt collector, they are generally ignorant of the law. But he's probably right in a round about way.
As you were correctly told by other posters, it's the state that the lawsuit is filed in. The question is then what states can they file the lawsuit in. The state you entered into the debt most likely has jurisdiction. The state that you are in now may also allow the suit depending on the nature of the account.
Further, in CALIFORNIA (as with many states), the time that you are not present in the state, doesn't now count for the statute of limitations.

