As I see it there are three possibilities.
(1) The AAIB drained some fuel and left some but didn't bother to say because it's not important. (2) Drained more than 95L but stated less - any figure up to that quantity is not logically incorrect - to keep everyone guessing. (3) Drained and measured all the fuel remaining and made a simple unqualified statement to inform pilots and operators the fuel tanks contained close to 95L.