I believe Nick is on the right track. I used that node yesterday and I was very happy it all worked well, or so I thought. Then I tested with a new file, added some doors in all possible positions, and run the script again. I only got out-swing doors, no matter how I changed their positions. So, I introduced a room in that space, and then I did get everything to read correctly. I opened the node for inspection and it contains a Python script node:
So it seems it is dependent on rooms, if there is none, it provides a default value, but it can be incorrect. Bottom line, to have this script run correctly I believe rooms must be present.