Funny thing was it wasn't scary at all, the steering just became a bit heavy. Looking at the tyre it wasn't flat to to the ground like a normal puncture (pressure was still 4.0). I'm pretty sure its not a run flat tyre but it acted just like one . If nothing else, NanKang make bloody rigid tyre walls . I'll keep a close eye on it from now on, the tyre technician who looked at it said both the inner and outer walls were undamaged and the rims didn't have a mark on them. I did have a blowout in Colorado, 2007 and that was a real heart stopping moment, tyre just disintegrated .
Pete