Dai Davies, the former head of royal protection for the Metropolitan Police, says accidents like these are embarrassing for the service, but that training for officers is very rigorous.
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It's judgement day at the Millennium Stadium as Cardiff Blues take on the Ospreys and the Newport Gwent Dragons face the Scarlets.
Showers expected throughout the day especially in the north. Drier and brighter elsewhere but cooler than in recent days.
Most places will become dry overnight, although it will remain generally cloudy with patches of hill fog.