I know many Contractors Insurance Policies have clauses in them which denies payment of insurnace claims were negligance is involved and proper safety precautions are not taken. Very prevelent in plumbing and electrical contracting Insurance.
Have a relative who owns a plumbing company and got injured in a ditch collapse and insurer would not pay out becuase he did not have proper bracing in place as required by OSHA. Not to mention the $25,000.00 fine OSHA levied on his butt as well.
After reading all the clauses and addendums in contractors insurance you wonder why you even buy it.
But the whole Ideal is for contractors to follow codes and regs to prevent problems in the first place.Insurance is for the unexpected even after you have done everything correctly.As most Insurance companys view it from talking to various adjusters etc.