The tech lead is not the one being interviewed here. Presumably, they are already respected in their workplace, and admitting that they learned something from t

The tech lead is not the one being interviewed here. Presumably, they are already respected in their workplace, and admitting that they learned something from the candidate's full answer should be seen as a positive by their manager. The way the candidate frames the answer is important here, so no-one seems stupid for holding a common misconception. And if the tech lead can't admit in front of their manager to not knowing everything? That's a sign of a toxic workplace. I'm not ashamed to admit that I have previously found myself in a situation similar to the tech lead: the interviewee gave a solution that I didn't know about - one that could be considered better - and my manager was in the room interviewing with me. I told the interviewee that this is a new direction I haven't thought about until now. It's important, otherwise we can't continue an honest discussion about the solution.