this was <at a> <the><a> moment when…

[nagomi]

"There was no explanation. And this was at a moment when companies were all desperate for workers and raising wages everywhere. Brian was shocked, but also not that shocked."

Context: This is what someone named Brian has gone through when he was working for a rental car company and he had his pay cut in half. It was notified to him a couple minutes ago. The quote is the part explaining it's strange because that's the time when all the other companies were struggling to find workers, offering better benefits and salaries.

Question: What effect does "at" in bold generate? I suspect I probably would've put "the time" just "the moment" without "at"

ie) And this was the/a moment when companies were all desperate for workers [...]

Source: Why worker productivity has fallen in the U.S.

 

[Uncle Jack]

"At a moment" does not really add anything, except that it attracts readers' attention.

The clause needs a time adverbial. This could be a "when" clause, or it could be an adverb of time ("yesterday", for example), or it could be a prepositional phrase, which is what this sentence has. You cannot just use a noun.

"This" refers to the actions previously described, including getting no explanation. It isn't a time or an occasion (for which "this was the time when..." would be fine), but it happened at a time.

 

[PaulQ]

And this was at a moment that = And this was at an example a moment / one of those moments
And this was at the moment that =And this was at that particular moment