I don't think it was pre-recorded exactly, but I do think they built something for the demo that responded to specific spoken phrases with specific scripted responses.

I think that's why he kept saying exactly "what do I do first" and the computer responded with exactly the same (wrong) response each time. If this was a real model, it wouldn't have simply repeated the exact response and he probably would have tried to correct it directly ("actually I haven't combined anything yet, how can I get started").