Said "I don't know" in a round last week instead of talking my way around it

Question about database isolation levels. I know roughly what they are. I do not know them well enough to be interviewed about them.

Old me would have circled the topic for three minutes hoping to hit something. Instead I said I've never had to reason about it past the defaults, here's what I do know, and here's how I'd go find the rest.

He said "fair enough" and moved on. The whole thing took fifteen seconds and we got through more of the interview than we otherwise would have. Got the offer last Thursday.

Not claiming this works every time. But the bluffing definitely wasn't working.