I’m very forgiving of a boy who lies simply because he’s scared, it’s calculated dishonesty, I find truly objectionable. Just saying “I didn’t do it” and hoping there’s enough reasonable doubt to get you off is almost within the ‘rules’)
As for the clip from Fighting Back, the punishment, in that case, does not strike me as incredibly severe (although seven strokes would have been a violation of common practice, if not actual regulations at the time depicted – we don’t see all seven stokes, of course, and if I recall correctly from when I saw the entire film years ago now, the boy throws a massive tantrum and the punishment is aborted) but the manner of the teacher, in that case, is, in my view, unacceptable.