The basement bedroom was where some of the assaults took place.
http://www.wjla.com/articles/2011/11/mother-of-alleged-sandusky-victim-to-speak-69038.html
I understand. But his being caught there - which I think undoubtedly happened - is not documented by multiple witnesses.
Not so the other locations.
In other words - it appears the only place he was active but not caught is at home. Makes home the anomaly - since we know he did it there.