It seems odd to me, that .GOV can change the conditions of a contract and change them mid stream. If a contract bid has been accepted by both parties, it is binding until both parties agree to change it, no?
Apparently you have not held/managed a multi-billion dollar contract. Language to the minutia all managed via risk/reward. In bad times we dictated the language (oil low), in good times (oil high) not so much.
