Wouldn't that be a ground if its connected to the transformers metal case?
You may not realize it, but that question strikes a nerve.
Many utilities use a distribution system called "Multiply-Grounded Neutral". There's a Y secondary, often ~15kV phase-to-phase and ~8kV phase-to-neutral, and the neutral is connected to a ground rod at each pole where there's a transformer.
It's controversial because the inevitable voltage drop on the neutral* wire is imposed on the Earth (the planet, the soil; not the GEC or EGC) and creates voltage gradients in the Earth. These can wreak havoc, not the least of which is electric-shock drowning. Most people who have ever chased down one of these stray-Earth-voltage gremlins would like to see transformer primaries fed from two ungrounded phases and isolated from the Earth, but
that conversion won't happen overnight.
* (they're widely called "neutral" wires, but they're not actually neutral unless all the ungrounded phases are perfectly balanced; (harmonics and all) they're almost always carrying a significant amount of current)
That said, implementing multiply-grounded neutral was a big improvement over Single-Wire, Earth Return. It could be a cost saver (one copper wire, not two) when servicing a small far-away load, but the energy losses, stray-voltage problem, and farms no longer being small users led to it being mostly abandoned.
