Lawyers for the Ministry of Business, Innovation, and Employment challenged that decision, and the High Court has now said Engineering New Zealand, the name the Institute now goes by, was wrong to drop the complaint.
Susan Freeman-Greene, the chief executive of Engineering New Zealand said no-one at the Institute was happy with the way things played out in 2014, and they would now reopen the complaint.
Ms Freeman-Greene said they now have the opportunity to go back and test the professional conduct in the situation, which she said was in the public, and profession's, interest.
In its judgement the High Court said that allowing disciplinary proceedings to be brought to a premature end by a member resigning would flout the trust society places on professionals, and bodies such as the Institution.
Maan Alkaisi's wife, Maysoon Abbas, died in the CTV building and his family is one of 54 who have been pushing for the Institute to follow through with the complaint.
He said the families had pushed for years for the complaint to be reopened.
"This is exactly what we wanted... We also commented on the resignation of Alan Reay at the time, and expressed our concerns that engineers should not escape responsibility by simply resigning when it suits them."
RNZ spoke to Mr Alkaisi at the site of the CTV building, a place Mr Alkaisi said was very special to him.
"It is now converted into this garden. I would describe this, the flowers represent the nice people, the beautiful people who we lost, and that ugly concrete represents all the people who did not do their job."
Susan Freeman-Greene said if the process got to the stage where a disciplinary committee found fault, Engineering New Zealand would need to look into what actions it can take since Dr Reay is not a member of the organisation.
"In any event, a finding through our processes will be important in terms of what we can say about professional conduct in this situation and also and what learnings and information it provides us for professional conduct generally."
Alan Reay Consulting has rebranded as Engenium, and when RNZ contacted the firm Dr Reay was not available to speak.
In a statement from his lawyers Buddle Findlay, he said he did not resign from the Institute to avoid the disciplinary action.
The statement said, "the CTV building disaster could have been avoided as the evidence to the Royal Commission showed."
"That tragedy haunts Dr Reay every day as it does many others. He has done everything he personally can to identify what happened and how we can ensure this does not happen again. This has included funding independent research and investigation. However, Dr Reay refuses to be scapegoated for this tragedy."
Alan Reay has 20 working days to decide if wants to appeal the decision, and has said he was taking advice on appealing the decision to the Court of Appeal.
- RNZ
