Possibly. Workers’ compensation and third-party liability are different systems. A separate claim may exist when someone other than the direct employer is legally responsible, subject to state law and coordination of benefits, liens, or offsets.
No. Responsibility depends on control, contractual duties, actual conduct, the source of the hazard, and the governing law. The general contractor’s presence on the project is not enough by itself.
The investigation may include the manufacturer, seller, rental company, maintenance provider, employer, or other entities depending on the defect, maintenance history, control, and applicable product-liability law.