I'm not an expert in all areas. At the end of the interview we have a section where we let the discussion go into whatever technical area the engineer wants to talk about. It sounds like you're an expert in an area where I am not. In those cases I try to ask questions and push deep, but (depending on the topic) that can be hard.
edit: removed discussion of the specific topic discussed. Sorry, folks below are right
Expertise is something our model handles less well (it's much harder to standardize). This certainly results in us failing some great people (and it sounds like that may have happened here). I'm happy to talk about this more. Give me an email at ammon@triplebyte.com.