Oh, my entire leg inflated from the knee down - ended up thicker than my thigh and was agonising to touch.
Negligence was kinda the name of the game at British boarding schools until the late 90’s, and probably still is - “the parents will never believe it” works 99% of the time.
My sister was at a boarding school just 3 years ago and exactly this happened when she broke her ankle - the school nurse told her to get some paracetamol and sleep it off. After seeing the picture of it I had to ring them up, demand that someone take her to the hospital for an x-ray, and they of course sent us an invoice for £50 for "transport to the hospital" anyway. Nothing happened to the nurse even though I complained higher up as far as I know.
Possibly, I just didn't know this was an option at the time, I only complained with the school. And I really have neither the strength nor the conviction to do it now, it's water under the bridge as they say.