This can happen with a queue overflow in some systems. That is, after a while of being on hold for a specialist, the VRS (Voice Response System) just passes you to any open representative, kind of just to see if your question is of a nature that doesn't really need the specialist. Good ones will recognize you being transferred back to the specialist queue from inside, though and flag that you're to wait for the specialist this time instead of going back to open general reps.