Bad luck.

What I'm more interested in is how they got in in the first place. Is there some trick that lets them get around the frameless windows or something to the door lock? Perhaps from the window on one side to the door lock on the other with a long pole/stick or something?

WRXes are frequently knocked off and used for ram raids over here - to the point that Subaru started fitting immobilisers to models even 3 or 4 years old just to try and stop the insurance premium going through the roof. So they must be fairly easy to get into.