They have two data centres in active-active mode so one copies the other if need be. FIrstly they are both within a mile of the airport which is gross incompetence anyway
Why do you say that ? Why is it perfectly acceptable to have hotels full of people within an airport boundary but not datacentres that are some considerable distance apart ? Many companies have key IT nodes adjoining the airport and not one has been damaged due to their proximity to aircraft operations.
I used to give presentations to customers on the capabilities of a telecoms company who had their operations centre in Reading. One smart alec suggested that having a building so close to LHR was bad planning. I replied that MI5, Downing Street, Westminster, Buckingham Palace and Windsor Castle were significantly closer and the consequences should they be hit by a wayward aircraft were considerably greater. Nobody had suggested moving those functions to a place of greater safety.
There was one incident where an aircraft damaged a telecoms facility, it was the Algerian (?) freighter that crashed near Coventry (?) and took out a transmission mast. As the network was ring-protected, the customers didn't notice any interruption but that same operations centre in Reading knew that something had happened within an instant.