As said, don't know about it so you may be right, but my thoughts are this. Many times my power gets cut yet street lights remain on. This means that there is still power running through some of those cables. So, there must be different feeds on the poles, some for houses, others lights, others feeding though to other neighbourhoods etc? So, if someone illegally connects on the right 'wire' could they be immune to load shedding?
In purely residential areas such as Soweto the street lights and the houses are fed by the same transformer from the substation level. Since load shedding happens at the substation it will affect both.