Bloomberg Sr Software Engineer interview questions

I got contacted on Linkedin by HR and was advised o apply to a specific role after she sent my resume to their teams. This whole process was a big lie. They told me there will be a coding interview. Instead a guy showed up a few minutes late which could not speak English clearly (I had to ask him several times to repeat himself to understand what he was saying). He told me this is not a coding interview. I was surprised but I went along anyway. He started asking me to explain BigO of different STL containers ... so make sure to memorize those like a parrot. Then he asked me some multi-threading questions. It is very annoying to tell you the interview is about something and you are in that state of mind then asked totally different questions. p.s. He didn't know there is a language called Elixir and asked me about it when I mentioned I worked with it, like how is this relevant?