I don't see how its possible to have ions many times larger than electrons actually moving through the wire. I would go against with what they said there and call some BS. Unless in this question there is some sort of contraption with a wire enclosed within a salt bridge? Although it seems as though that may cause technical difficulties with the battery.
Think about it though: how can positively charged ions any bigger than an electron (even a proton, which is ~1800 times more massive than an electron; and electrons may not even have a conventional "size" we can even conceptualize) ever hope to move through the solid-lattice structure of closely packed, dense, positively charged atomic nuclei of whatever conductive material the wire is composed of? It simply doesn't make sense. The only reason electrons can even flow through the wire is because they may traverse the inter-connected network of orbitals present in the solid structure; how could protons ever do this? Furthermore, a salt bridge is meant to maintain electric neutrality.
For the wire to act as a salt bridge negative ions would have to flow through the wire in the opposite direction of electrons and simultaneously positively charged ions would have to flow in the same direction as the electrons -- all through the same material at the same time.
It just doesn't make sense. That's my 2 cents.
