I would think if A Installer cut his hand at someone's home doing A Install the Homeowner would be the first at fault.
My homeowner Ins would cover theis guy up to 100000
I am sure if he filed on them he would soon find out who and what co he worked for.
Most Contract's require Workers Comp. if you check. If you are A Independent Contractor you are exempt. But if you hire people you are not.