If it's that typical, then one would have thought that governments would be wise to it; after all, when push comes to shove, government wins (he who hath the guns winneth). If Panama couldn't figure that out, or if they stupidly agreed in the contract to pay for cost overruns over a certain amount then they have no one to blame but themselves.
They keep falling for it, time after time. I proffer a gentle challenge. Find me one big ticket government contract - civil, military, whatever - from anywhere in the world in the last 30 years that came in both on time and with no cost over runs.
You won't be able to.