All clear.

We spent the morning in A&E because there was no improvement over night.

After a while waiting, though not as long as I remember back home, he was seen by a supervised student Dr, then another, then a second opinion after X-ray to make sure he wasn't liable for compartment syndrome (where the internal pressure stops the blood flow from the capillaries, so while overall blood flow is still good, individual patches of tissue can die).

And then off we toddled, with a prescription of ice and elevation and ibuprofen.
Only took 90 minutes.
No exercise for a fair while, and he's warned work that he might not be much use, but we'll see how he goes by Monday.

Fingers crossed for a quick recovery.