In the days after the race I contacted the mylife Support line to discuss the failure.
The issue with the pump on the day was simple, it is designed to work between 4-40 Celsius. On the day the temperatures were struggling around 2-3 Celsius. Coupled with the fact that I was wearing the pump on the outside of my upper arm the pod was very exposed. Had it been on my stomach it might well have done better as there would have been some insulation from my body. They also suggested that in similar circumstances wearing a strap or bandage around the pod on the arm would have given it a little more protection from the cold too.
They then replaced the pod with absolutely no quibble.
Continuing excellent service and support for the Omnipod.