Shaw Constructors, a subcontractor, signed a lien waiver agreement with the general contractor (Kaiser) on a $38 million industrial project. When Kaiser failed to pay $5.3 million owed, Shaw filed liens against the owner anyway. The owner (PCS) tried to enforce the lien waiver as a third-party beneficiary. The Fifth Circuit ruled that Shaw could raise the same defenses against the owner that it could against Kaiser, including the right to rescind the subcontract for material breach and refuse to honor the lien waiver. This protects subcontractors from being locked into waivers when contractors fail to pay.
You can challenge a lien waiver if the general contractor materially breaches—such as failing to pay you—even if the owner tries to enforce it as a third-party beneficiary.
Material breach by the general contractor (like non-payment) gives you the right to rescind the entire subcontract, which can override lien waiver obligations.
Don't assume a lien waiver is ironclad against the owner; you retain contractual defenses based on the general contractor's performance, and non-payment is a strong defense.