Update,
now the ambient temperature is above 10 degC (well just up here in aberfreeze) the bike is behaving itself, so, as before, no recorded fault, no replicating the problem, nothing to be done.
On advice from the dealer I have written to both the dealer and Ducati UK to register the fault, so should it happen again within a reasonable time frame, but outwith the warranty the bike will be covered. Well thats what Duk UK wrote back and said.
Result..............probably not, but better than nothing, and I can get on with my summer
Russ