This is possible in the prison / camo-building at VMC for example:
Since this is a very frequented building, it's a cheating troll's paradise.
But I repeatedly also logged in the wall at the base of Green Mountain tower although I logged out inside the top room with the control panels in the wall.
I also experienced the police station in Nadelino. Logging out at the back of the bottom floor behind the stairs there always caused me to log in under the floor.