If Finnair issued the ticket, they sold transportation between the two points. Generally speaking, airlines take responsibility for itineraries they issue if they have another way to book you, particularly if they can do it on their own flights.
The cases where refunds are generally offered is when service is entirely discontinued to a given city. So, if Finnair doesn't sell tickets to the location where you're traveling, they can just refund you.
It gets to be a "gray area" when they sell codeshares through another partner, but even in this case, airlines will usually take care of you in the interest of customer service.
Originally Posted by
seawolf
Do we know that for a fact or just what we want it to be?
Depending on auher's complete itinerary, the only obligation AY have could simply be a refund. There has been a couple of reports BA offering refunds as the only option on Avios tickets involving AB transatlantic flights despite BA serving the route via LHR.