Mistakes happen. Its a fact of life and we are all human. Whats important is nothing came of it. He went around and that is that. I was on a flight recently (light turboprop) and the aircraft was cleared to line up behind a heavy and then told to take off asap as there was a heavy on a 4 mile final. The turbo could not comply due to minimum spacing and had to vacate the runway only just avoiding causing a go around.
Its just a mistake and they happen. Cant be helped but I dont really think its a big deal as long as everyone carried out the required procedures safely then all is good!