Key,
Yes, greatly embarassed by that. When starting out I put a fair bit of weight on the front, and the front tyre slipped, so I thought I had a soft tyre. When out in front for I guess the second lap I thought I felt it slip again, and thought "get down on the blue board", then realised I was travelling too fast. Won't happen again - Mr C Chapman has schooled me on what to do in future, if I actually have a puncture.
Shame - I was feeling strong, and my big backside is a wide load to overtake on such a tight track...
MC