def not an EE, but the room is not an accident either.
it's defined as an actual room, called the null room, and the exits are all pointed to itself. and, when an object is supposed to be put out of game play, it is assigned to that room. the object continues to do what it does (like bad guys still walk around in it, etc) you just can't ever get there. and, the objects can't ever leave on their own either. so it really is a "jail" in a way.
when you overwrite location $9B with the number 0, you assign Clark's room number to the null room. It is given the graphics pointer of Subway, and color orange, so it is definitely a deliberate choice of the programmer to make it a room.
The clever part is that with only 4 or 5 lines of definition code to make the null room, the programmer gets the advantage of saving quite a lot of game play code by just throwing items in there that put out of play...then it doesn't matter how they walk around, they never interact with anything anyway...kinda slick.
anyway, hope you enjoy.
in Adventure, there is a similar room...it is the game select screen which has a number 1, 2, or 3 in the center. If you overwrite the player's game position to this room, you wind up in it and can't leave.
I wonder if Raiders has this...I haven't looked at it yet.
Haunted House has one, but it is not a deliberate programmer null room for that purpose...it is just a quirk that if you set the floor to 4 (which is actually floor 5), you wind up in a weird place.
fun stuff...