CPA Australia alleges NZICA defamed and breached the Fair Trading Act in statements in flyers, advertisements and at industry events which included false comparisons and misrepresentations of issues such as potential earnings, numbers of accountants, global reach and educational standards.
Gray said that CPA Australia's growth in New Zealand had been slower than expected and it "was looking for someone to blame". Comments to an industry event by NZICA's Patterson about rival CPA Australia were recorded by an audience member on his pen recorder, with the audio played to the court yesterday.
NZICA was merging with the Institute of Chartered Accountants of Australia at the time, and Patterson sought to explain the changes in the context of a more competitive environment.
In Gray's defence against the defamation, he said Patterson's speech carried qualified privilege, as it was heard by accountants who were able to make up their own minds, and the comments were genuinely her own opinion.
There was little proof that NZICA's statements had led to a loss of revenue, profit or goodwill, Gray said.
"Corporates have no personal reputation," Gray said. "They have no feelings to hurt."
CPA Australia's witnesses, who the court heard from earlier, were largely CPA Australia employees or officers, Gray said, who would have heard the speech with "a sensitivity to things said about the plaintiff but the ordinary listener is not like that".
NZICA published advertisements in October 2012 to coincide with its rival's accreditation by the FMA, stating "in accounting there's best practice and then there's second-best practice" which claimed only a member of NZICA had been exposed to the highest levels of industry training and development, which is why top CFOs and CEOs only employ chartered accountants.
Yesterday CPA Australia's legal counsel, Alan Galbraith QC told the court NZICA engaged in "professional denigration" that was "quite extraordinary and offensive" against rival accounting body CPA Australia when it was at its most vulnerable in the early stages of expansion in the local market.
Gray said he intends to call 10 witnesses.
The case continues.