The performer may have been oversensitive to disturbances. But if you are a nervous or inexperienced performer attempting something demanding then it is very easy to be "rattled" by what to an outsider might seem insignificant distractions. The point is, the man was trying to perform in a concert situation (not a session or singaround) and was entitled to expect the audience not to put him off. Playing in a public bar or a session is different, a performer has to accept that there may be other distractions, but equally he is probably under less close scrutiny and under less pressure than when on a concert stage.

His response may not have been very tactful. Teachers have a tendency to forget when they are dealing with adults. But it seems to me that Pierre is trying to put the blame on the performer for his reaction, rather than accepting that it was his behaviour (which I'm sure was unintentional) which triggered it in the first place.