Without reading the contract specs or anything, I would think their would be withholds
for tardy/sloppy work. Or even bonuses if things came in under budget or even on time.
It's probably fair to put some of the blame on the gov't project management (or lack thereof) but it's probably also true that the vendors should have started calling out warning signals knowing how bad it was progressing.
Another "lesson learned" and quickly forgotten. Another chapter in the "Worst Practices" best-seller.