In the IBC, Article 707 covers stairwell shafts. In Section 707.8.1 it is prohibited to have any penetrations into the shaft assembly except for those necessary for the purpose of the shaft. This includes any receptacles or switches that only penetrate from the room side. To do it right, you must use a surface wiring method, or a false wall would need to be build (hat-channel) on the outside surface of the rated wall that encloses the stairwell.
The local BO is cutting you some slack here. Putty packs are not really allowed either. he is using section 104.11, which allows for the use of alternative materials. As a BO, I would not allow this, as it isn't equivalent nor complies with the intent of the code, IMHO.
