Wow... was this an actual hiring manager or someone, or like an HR person with a checklist?

I've interviewed for one or two Elixir positions where the opposite thing happened: I talked with someone who had a checklist. I haven't done Elixir professionally even though I have extensive Erlang experience and that was that.

There is a pretty stark difference between "has architected an application with OTP components" and "can write linear code in Erlang or Elixir", but even then you'd probably be able to fit someone in unless you're hiring for that kind of senior/architect position.