AFAIK, the teleporter trick should work; at least one person got in/out that way through the window.
There should have been a couple assassins attack you shortly after leaving the doctor's house. How far away were you when you teleported out? Maybe if you place the other teleporter stone just outside the house it will work better? Or use the teleporter pads to get back to Ars Magicana and run to see Commander Ralph?