That is simply not true. I was there, in the inside and I have very vivid memory of what Diamat did in that referral and how he conducted himself both in the inside and outside in public. Diamat was not criticized for giving his opinion, but for demonstrating that his opinion has been compromised and that he should have recused himself from the case because he was compromised and he was criticized for how he reacted when he was made aware about this. That became ever more obvious during the case and culminated when he broke the tie. Then it was the opinion itself, that was criticized and not fact that he gave it. And I assure you, if he would have not given his opinion, but would have only broken the tie without doing so, he would've been criticized for that even more so.
The fact that the Curator is perfectly able and allowed to give his opinion does not in any way, shape or form exempt his opinion from being scrutinized, criticized and if he cocks up, ripped apart - that's part of the position, if you cannot take the consequences your own opinion has and your decisions cause, then you are simply not up for the job - and that is what Diamat failed to realize. I suggest to be careful before building myths based on obscured facts and factually falls premises.
Just for reference the relevant referral threads,
#1 &
#2. You can look up the townhall discussion in this very thread here.