Probably you can claim twice, though it depends a bit on the details. If, for example, you were reticketed on to flight2 and then onto flight3 then that's two incidents, two claims for compensation. If flight2 was always down to be late and you were not reticketed, then there may be a different answer. But broadly speaking, 2 separate events can result in 2 payments. I would expect BA to pay one of these fairly easily, the second may need CEDR involvement. As ever, never ever act in haste just after a cancellation, there were other people rebooked on to El Al on those dates.