But he noted evidence from psychiatrist Dr Philip Brinded that Love's mental abilities "appeared to far exceed those of other defendants found unfit to stand trial", and found that there was no "material error" in Justice Lang's "very careful assessment".
In any case, Justice Harrison said, the Crown's primary evidence against Love was based on documents, not on what was said at the trial.
"The contemporaneous documents were the most reliable and, for Dr Love, damaging aspects of the evidence," his decision says.
"Dr Love's defence was essentially one of denial of knowledge. Contrary to Mr Krebs' submission, Dr Love's restriction to that line of defence was not attributable to his mental impairment but to the circumstances of a strong Crown case.
"And to advance an affirmative defence would have been contrary to his defence strategy of denial; he cannot have lost an opportunity which he never had."
The Appeal Court found that Love did not need communication assistance.
"The transcript discloses Dr Love's ability to understand and respond to questions, often of a testing and adverse nature," it said.
It also found that there was no miscarriage of justice arising from the decision by Love's lawyer at his first trial, Colin Carruthers QC, not to call evidence from Auckland developer Tony Gapes, lawyer Michael Reed, economist Martin Lally and Wellington Tenths Trust manager Liz Mellish.
Finally, the Appeal Court ruled that the two-and-a-half-year jail sentence imposed by Judge Lang was "well within range if not merciful", and could not possibly be criticised as excessive.
The decision said prison authorities were "taking all proper steps to ensure Dr Love gets the appropriate level of health care".
"There is no evidence that he is suffering unduly; to the contrary he appears to be in relatively good health," the Court said.
"The prison environment has been able to accommodate the dietary demands of his diabetes and other conditions."
- Additional reporting Katrina Bennett
