Is it unusual for a moderator to ask for credentials or other user specifics related to the topic of an SE site?

Writing this answer, as a somewhat old member of AI.SE, I don't know much about rules of SE, but I would like people to consider certain past events before answering (I have tried my best to be unbiased):

1. AI.SE has had a history of users pretending to know a lot and writing answers very vaguely related to the question asked, and also upvoting each others' answers. This situation was pointed out by a well reputed user (who you can consider unbiased). This resulted in temporary bans being handed out, and when this still did not stop then permanent bans. This involved a lot of back and forth between users and mods about what the decision should be.
2. Our site is very small and non-rewarding, there have been multiple experts who have came and gone (but hangs out in other SE sites). So this has resulted in a severe lack of community moderation. Only nbro is the one who has been cleaning up the site. Due to the hype of AI, a lot of low quality posts are posted everyday, nbro is the one to rectify it, delete it, etc. He does this without any returns, it is just a labour of love I guess? Is this ideal? NO! But our site literally has no active mods (except nbro). No one wants to do the job either because of time constraints, or because they are not knowledgeable enough to do the job.

My opinion on this matter is: nbro's behaviour was definitely unwarranted and he should apologise. But I feel that one should cut him some slack, he has to deal with low quality posts with the same mistakes everyday. nbro does appear to be rude and blinded by his opinions at times, but it is the best we have. He is the only one who stepped up to the job and is singlehandedly keeping AI.SE going. I think nbro made a poor and impulsive decision (which he might not have made, if he did not have to deal with a deluge of low quality posts every single day) and I hope he apologises so that we all can move on.

I've been moderating chat in some level as a RO and mod for almost the entire time I have been a member of SE, so I have some views

To a really large extent, we expect/allow for 'local' mods and community regulars to self regulate chat - while its easy to go "but I don't like that?" to some extent respecting their requests is pretty much an essential part of a smoothly running site.

If I ask someone not to do something - I'd expect folks to take it into consideration, (and for my regulars to tell me off if I overstep) - not dig up every instance I've done it, with no context.

Least within my community, a significant part of my success factor as a chat mod does come from a certain level of

"I think it's important for me to understand our users, what they have studied and what they are currently doing, so that I can judge more correctly their activity here."

In a positive aspect - I know their interests, and what they hope to gain from being on chat, as well as "issues".

On a negative aspect, its useful to know the quirks of users and whether they might be trouble.

One of the chatrooms I've had have had folks whose entire interaction with us tending to be asking "low effort" questions (which is something we explicitly discourage) or linking posts for attention.

While I don't think the wording is very, well politically correct, I get the sentiment.

On the post that's referred here, while I haven't looked into it- there's a big difference between cross posting stuff from a younger beta for attention, and because that specific post may be of interest to someone. The tone OP takes is a bit... "but you do it too!" which is unhelpful. It might be useful for them to step back, try to get what the moderator is trying to do, and find a compromise that helps both of them meet their goals.

And well, fundamentally - the buck stops with the moderators of record, and if things go horribly wrong, they're the ones picking up the mess. Have a little faith in them ;)