Hot N High, the accident in question is here
AAIB.
A more complete analysis of the accidents in the CAA's latest 10year fatal accident summary shows twoweather related accidents for IMC rated pilots
There is one CFIT for an IMC pilot (An IMC pilot and instructor on an IMC re-validation)
There is one loss of control accident (the above referenced Mooney engine failure in IMC).
In the same period of time there were
1 CPL/IR CFIT
1 ATPL loss of control in IMC
1 CPL/IR Loss of control in IMC
9 PPL CFIT in IMC
2 PPL Loss of control in IMC
There is no data to suggest the relative exposure of PPL, PPL/IMC,CPL/IR, ATPL to IMC conditions in GA operations.
Interestingly there were also 6 accidents in the CAAs analysis that ocurred outside the UK and look like weather accidents (eg. 'crashed into mountainous terrain in deteriorating weather') for which inadequate information is available to be analysed.
Recently there have been a number if 'foreign' weather related accidents involving UK based pilots. As these are investigated by agencies other than the AAIB or the NTSB, the reports take ages to come into the public domain (and even the AAIB can take well over a year).