The good/bad news is all that I can find in any event logs is "The SQL Server (MSSQLSERVER) service terminated unexpectedly. It has done this 1 time(s)." There is nothing else. The dump indicates no CPU or memory pressure. There is nothing written to any of the logs within an hour of this occurring and in the SQL logs there is the backup that ran 6 hours before the crash and nothing more.
And the great news is the DB backed up successfully and restored successfully onto another server so with DBCC checkdb returning no errors and the data appearing to have no corruption.
The client has no extended support contract, just what is provided with the licence. So is there any where that I can raise this one directly with MS?