Why do you have to prove it to a contractor with a photo?
“IRC 2006 M1501.1 Outdoor discharge. The air removed by every
mechanical exhaust system shall be discharged to the outdoors.
Air shall not be exhausted into an attic, soffit, ridge vent or
“IRC 2006 M1506.2 Recirculation of air. Exhaust air from bathrooms
and toilet rooms shall not be recirculated within a residence or
to another dwelling unit and shall be exhausted directly to the
outdoors. Exhaust air from bathrooms and toilet rooms shall
not discharge into an attic, crawl space or other areas inside the