Not so much a specific incident but I had a a person I considered a really good friend. He became an elder and completely changed. He went from encouraging to judgemental pretty much overnight.
A little backstory, he was an older man who, I believe, had been an elder previously and lost his privileges for what I can only assume was some stupid reason. His son was one of the most arrogant elders I knew. And I suspect he had something to do with getting his father removed.
Another time an elder and his wife inadvertently came to my door while preaching. At the time I was DFed and not going to meetings. I let him know I was DFed and then to my surprise he offered me a bible study. When I questioned it his wife assured me that he was an elder and it was OK for him to study with me. Still being mentally in I accepted. He came back as scheduled, but instead of having a study, without a word he handed me a meeting invitation and walked away.
Interestingly, later I applied for reinstatement and he was on the committee. I remember him saying "it's the truth, it's the truth, it's the truth". The way he said it I found myself wondering who he was trying to convince. Me or himself.