No - once implemented that is it. If it costs a lot more, Contractor could try to claim that was due to other reasons that could be a compensation event but the PM would have to agree that it is indeed a new compensation event and request a quote.
The only remedy at that point would be by mutual agreement - but not sure why the Party that has benefited would ever agree to something different if they don't have to.
The only remedy at that point would be by mutual agreement - but not sure why the Party that has benefited would ever agree to something different if they don't have to.