In reply to TobyA:
My father in law had a similar thing happen to a set of Mavic Ksyrium Elites which had probably done <10k km on nice, smooth roads, so it does happen. In an aluminium rim my guess would be some fatigue mechanism to blame.
Regarding re-building a wheel, I haven't crunched the numbers so I can't tell you if it's cheaper to get a new rim or not, but it's remarkably not difficult if you can get a rim the same size (and therefore letting you re-use the spokes). I turned the guts of the freehub on my MTB into shrapnel a couple of years ago (definitely due to my relentless power output and nothing to do with poor maintenence... ahem...) and decided to just get a new hub and build it myself. It cost me about 20€ for the new hub, and a Friday night in front of the telly to take apart the old rear wheel and rebuild with the new hub. I guess about 3 hours and 3 beers and I had a new wheel with <+/-0.5mm radially and axially. I do a decent amount of bike tinkering, but never got close to building a wheel before, and it was nice to tick that box too - very satisfying. I borrowed a truing stand for the job, and followed the Art of Zinn, but I bet there are any number of YouTube tutorials. Getting it true is a bit like solving a rubix cube - it appears mysterious, but there's actuality a fairly systematic methodology you can follow and then it's just "cranking the handle", so to speak.
So the question is, are you as stubbornly tight as me? Could you even put the Hunt hub in your old Boardman rim?
Edit: Typos
Post edited at 21:26