(b) he could have walked to school in the other shoes and changed into the proper ones once he got there (to avoid wet feet).
Because often schools have rules about having to wear correct uniform to and from school.
OP
I'd go with asking them to clarify their policy on 'emergency uniform issues', ie when a piece of uniform is lost or damaged and cannot be replaced immediately. I'd then go on to give a number of unreasonable soloutions.
When you received the uniform list there didn't seem to be a policy for this.
Should the child be kept off school until the item is replaced? Work could be sent from teachers as it would if the child is in isolation.
Would this be reported as, 'educated off site' rather than unexplained absence?
Perhaps the school could take the child shopping and then bill the parent? Obviously this would be a payment spread over a number of weeks so families can afford it.
Perhaps they could link to a local shoe shop, the shoe shop can be called in to bring a selection of suitable shoes.
Maybe the school should keep a selection of shoes to be worn, a similar system to when you go bowling.
Maybe they could arrange for a local shoe shop to open up from 10pm to 8am in case any child's shoes need replacing overnight.
OP
It's ridiculous, I'm a bad teacher when ic comes to uniform, I never look at shoes and only ever pull students p if it's something like a bright pink hoodie.
I'm supply so I don't always know the actual detailed uniform but most of the time a child will approach me at the start of a lesson with a note or a message in their planner from head of year stating why the child is in bright pink trainers or isn't wearing a blazer.
Oh and I also start lessons now with, "If you want to remove your blazer you can, you don't need to ask me" because that's another fucking stupid rule.