I didn’t read it – did they disagree with the emotional ramifications, or feel the results warrant it ?
Your child is not your property. Full Hilchos Bein Adam L’chaveiro apply to him. Embarrassing him in public is almost never justified.
Toi – yes, I grew up seeing this type of thing happen, not to me. It is abundantly clear that the feelings it engenders are absolutely not worth any possible short term gain.
And before you sarcastically call me an expert mechanech, I’ve heard an “expert’s expert” in chinuch refer to such punishments as retzichah.