"Routing has to be multi-city"

Worth doing a check on these with something like ITA Matrix against a pure rountrip and asking why? or Maybe WhyQ or WhyR? ;-)

Not sure if the ~$700 per direction is the lowest base fare on which you can get this to work, but obviously with a $480YR (total for both directions), this is not a bad set up for a potentially even cheaper ticket.