Mine virtually seized on 164 miles. Didn't actually lock up, just made a big clattering noise then grated very painfully as we crawled to a nearby pub car park.
On the Bevel Box thread I subsequently started someone did report that theirs seized and caused the car to spin 180 degrees.
From what I was told at the factory, very few Bevel Boxes have actually seized up. Mine was classed as seizing up.
You look to have had a lucky escape, but still a very scary experience.
Hope they get you soon back on the road