This answer as put up by Mike Tiplady and emailed to me, but for some reason did not show up when I went to the question:
"it depends on what the Adjudicator was asked to do and what he did do. if he was asked to just say that the PM was wrong then the Adjudication hasn't really taken the matter any further. If you are adjudicating then the best thing to do would be to make a determination of the actual value of the CE. You may need to consider this aspect further.
Section 108(3) of the Construction Act makes any award binding upon both Parties so if the Adjudicator has made an Award it needs to be put into effect by both Parties and that would include the PM and the QS."
"it depends on what the Adjudicator was asked to do and what he did do. if he was asked to just say that the PM was wrong then the Adjudication hasn't really taken the matter any further. If you are adjudicating then the best thing to do would be to make a determination of the actual value of the CE. You may need to consider this aspect further.
Section 108(3) of the Construction Act makes any award binding upon both Parties so if the Adjudicator has made an Award it needs to be put into effect by both Parties and that would include the PM and the QS."