Oh my gosh - that poor kid !! and those other kids were exposed to that brutality as well. It seems likely to me that this wasn't the first time this child was spanked like that - just not in front of a crowd. And the adult even warned the child that she would do this awful shaming act .. and still the child behaved poorly in school to the point where the aunt was called. So .. I would say that this particular situation would lead me to conclude that spanking - even extremely shameful spanking - does not "make" a child behave nor does it teach a child HOW to behave. Otherwise, I'm sure this child would have straightened up when the threat was made and behaved like an angel. I'll bet the child is still a behavior challenge at school. So all those spankings did not "learn him a lesson".
Poor kid - I hope he is in a better living situation now.