What a child wears is the parents decision. For the school to involve itself with the clothing or footwear is overstepping boundaries.
There are two exceptions:
If the school has rules about clothing, i.e. uniform, sports shoes for sports, etc… then obviously they should enforce them – without humiliating the child.
If a child misuses an item of clothing or footwear, say he throws his shoe(s) at a teacher or classmate, then obviously it is the educators right to proceed as they see fit. I have given another example in the above thread.
Confiscating footwear if a child comes late to school is definitely overstepping boundaries. The punishment is also out of proportion and unreasonable.
Always remember, a child’s ego is very fragile, and humiliating them in public is never a good idea.