A water line installed by Dynamic Systems broke and caused $800,000 in damages. The property insurer tried to sue Dynamic Systems, but Dynamic Systems claimed a waiver of subrogation clause in the main contract protected them from liability. The court ruled there was a factual dispute about whether the water line work was done under a separate contract that didn't include the waiver clause. The case was sent back to trial because the facts weren't clear enough for the judge to decide it alone.
Waiver of subrogation clauses in main contracts may not automatically apply to all subcontractor work—especially if the subcontractor performed work under a separate agreement.
Document every contract carefully. If you do work outside the original subcontract scope, make sure it's clear whether the original terms (including waivers) still apply or if you have a new, separate contract.
Summary judgment (quick dismissal before trial) can be blocked if there's any genuine dispute about which contract governed the work. Keep detailed records of what contract covered what work.