Sorry we're late on this. Good question.  The payment clause for construction contracts is a bit unique in regards to certifying the payment of subcontracts because of the historical nature of the construction industry where payments to subs have been a problem.  That problem is nowhere near as prevalent in the A-E industry and many others.

52.232-26 -- Prompt Payment for Fixed-Price Architect-Engineer Contracts.  Provides the guidance for invoicing and payment. While the government does not have privity of contract with the subcontractor, in the event they didn't pay their subs but asked the government for payment based on costs incurred from their subs... that would be a false claim.  The subcontractor could take the prime to court for payment and other late penalties and the government (if we choose) could provide evidence we did pay the prime.