If the airplane has had a maiden trim flight and needed mechanical trimming (as knightmagic has stated) , your not going to be re-setting the control surfaces to neutral, you have already moved the control surfaces to the new trim settings. Telling him to set them again is a step backwards.

I'm confused about how much experiance knightmagic has and the truth is; only he, or pilots helping him, will know. Maiden flights are exciting and one of the greatest joys of this hobby! I think it a good idea to have a good pilot stand next to you for the flight you are attempting, if you have some doubt about your abilities. Crashing a new plane because you were not ready to attempt what you are thinking, is not necessary and should be avoided if possible!