Is there an exception to the general rule where the acts of the subcontractor create a public nuisance and are known to the contractor?

While we have been unable to find in California a case applying the above mentioned exception to the general rule, there are cases here holding that such exception applies where the acts of the subcontractor create a public nuisance and are known to the general contractor. See MacLean v. City & County of San Francisco, 127 Cal.App.2d 263, 273 P.2d 698. Logically there is no difference between a situation created by a subcontractor known to the general contractor and dangerous to third persons, which amounts to a public nuisance, and a similar situation which, while dangerous to third persons, does not amount to a public nuisance.