I am lucky that no GC has tried to pull that on me. I have had H.O try that I told them that the job would cost more if they did any of the work, my name is still on the job if they put the outlet cover on and slipped on killed themselves. Next you know the other half is suing you because that was part of your job that you did not do. Even though they told you not to, courts normally will believe the H.O over a contractor.