Note
Got some course marahals out to their locations for school cross country, then jogged the course backwards to get back to the start. Just turning onto the bridge (right in front of another marshal) when I rolled my ankle and heard a distinct 'pop.' May have yelled a bit, but tried not to teach anyone any new words.
An unusual one for me - it was with full weight on my heel. Hasn't really puffed up much, despite the pain at the time, and weight bearing was not 100% comfortable, but very possible (I lapped the course again a couple of hours later to de-flag it).
One localised very tender spot below the lateral malleolus, but seem to have dodged a bullet. Maybe just tore some scar tissue? If there's anything wrong with a ligament, it must be one where I didn't have much left anyway.