How would such a violation be corrected?

I assume a special box is already sold for that type of configuration or a reducing connector? Or do you feed the fat pipe into a junction box first to tap into the thinner pipe and then from the box to the elbow?

If not....how would you go about puting something like this together properly? [Linked Image]

Asking out of curiosity, not that I'm going to actually go out and do this for someone.... [Linked Image]