I would question the truthfulness of that statement and would have to see it in writing, signed by the plaintiff to believe it.
I work with subs all the time, and the firm I work for is, many times, a sub. It would not be SOP for any prudent subcontractor to write a contract that large with their payments based on someone else's schedule. Most subcontracts have their own payment schedule, based upon a percentage or stage of work completion, with final payment - the standard 10% retainage, due after all/any punch-list items are completed.