mmm, a russian submarine... or another blue-on-blue?
Back in the days, they blamed the soviets also, but own boats are mostly responsible.
The day an Irish fishing boat was sunk by a British submarine (Specially this one - mostly because HMS Porpoise was hidden after the incident, but one worker spoke to the press about the damage, and no longer the soviets were the culprits)
Revealed: MoD admits to 16 nuclear submarine crashes | Herald Scotland
So on and so on.