Inspector John Braithwaite recommended approval of the office, retail and residential development following a public inquiry last year. Planning consent was subsequently granted by the secretary of state.
But objector George Turner claimed Braithwaite had failed to treat objectors fairly and had given an appearance of bias.
Turner mounted a judicial review challenge and High Court judge Mr Justice Collins criticised the inspector in a decision last year. He said Braithwaite's conduct "fell short of that which should have been displayed" and that the appearance he gave of favouring the developers was "most unfortunate".
However, the judge rejected Turner's challenge, saying that Braithwaite's conduct was "consistent with judicial misconduct as opposed to bias".
Dismissing Turner's appeal against that ruling today, Court of Appeal judges ruled that the criticisms of Braithwaite's handling of the inquiry were misplaced.
Lord Justice Sales said: "None of the matters relied upon by Mr Turner, whether taken individually or together, indicate that there was a real possibility that the inspector was biased.
"The inspector was acting properly and without giving any appearance of bias according to the relevant test".
The judge added: "The objectors to the scheme, including in particular Mr Turner, were treated fairly by the inspector both before and during the inquiry.
"We can detect nothing that was done by the inspector which gave any appearance of bias to the notional fair-minded and informed observer.
"We do not endorse the criticisms of the inspector made by the judge. In our view, the inspector's conduct cannot be castigated as something equivalent to judicial misconduct".
Turner v The Secretary of State for Communities and Local Government. Case Number: C1/2015/0892