All that matters is what is in the IMED/WHO directory, and that is Dominica. This is also what goes into all the "official" paperwork (ECFMG, NBME, NRMP, etc.). Ross has an office in Edison, of course, but they aren't "techincally" in Edison (despite the fact that the entire administration is run out of the U.S.). It's like how all of those cruise ships that pick up all their passengers in the U.S. and take you around the Caribbean and the Gulf of Mexico and elsewhere are all registered in Liberia. They do this to exploit loopholes, just like Ross. Think about it: a lot less than half of your "Caribbean education" actually occurs in the Caribbean.
So, you can't really fault someone for putting Edison, NJ, which is where the school is run and a better surrogate "campus" (in reality) being representative of the greater and more significant portion of a Rossie's medical education than the portion done in Portsmouth, Dominica, West Indies. But, even though one might let it slide, it's still not accurate... even legally (i.e., you'd get blasted in court if you attempted to mischaracterize your school by stating, in your CV or otherwise, that it is "located" in Edison, NJ).
-Skip