Do procurement contracts have clauses that discount the purchase price when proprietary information is lost to reflect the diminished value of the product?
I wouldn't be suprised. I've done some unclassified govt contracting and it wasn't uncommon for them to include clauses in software purchase contracts that they had to be re-imbursed a certain amount of money any time a security vulnerability was discovered in the purchased software. The reasoning was that they had to spend money identifying, reporting, and updating systems, so the vendor had to pay for wasted resources.
This is an excellent question. I can imagine the difficulty of such clause would be to quantify the value that was diminished due to a breach in financial terms. Most likely the case is that the government has a vested interest in keeping tight security over their program - from engineering to manufacturing and small suppliers rely on security engagement from the gov. Big suppliers such as General Dynamics and Northrop Grumman, I am sure security breaches are taken very seriously and it would impact future supplier selection process and bidding.