It was backed up by several other ambitious things they did, like bombing the island runways ahead of time by using 9 long range air refuellers to get the bombers a much greater distance than they should have been able to go (something that hadn't been done before). Also the island defence weren't exactly expecting shit so those bombing runs happened completely unopposed as the island troops didn't really know if they were allowed to engage back.

By the time they got their act together the bombers were leaving and ditched into the ocean on the return to be picked up by ships.

A lot of British campaigns use weird tactics and strategies that pay off. They can be quite creative. Quite different to the massive overwhelming saturation tactics of the americans.