Bottoms Up

Despite playing a schoolboy, Melvyn Hayes was 24 years old at the time of production.

When the boys are rioting in the school yard, they are deemed to be using radio controlled model planes to attack the teachers. As the models fly low over the top of the teachers who are crawling low along the ground, (it would not be allowed these days) the models are clearly not radio controlled models, but rather the control line variety. Their circular flight path makes this very obvious.