TD: to answer the same questions a slightly different way from the text you quoted and what Dodgysooty wrote re ground crew:
Q: Why was AAR withdrawn
A: Standard procedure while we ascertain a source of ignition in the areas of possible fuel leaks and the possible reason for the fuel leaks and try to remedy as quickly and safely as possible.
Which was found and isolated pending the result of the BOI, according to what you wrote and a solution is/has possibly been ascertained.
Q: As AAR is considered not safe can the Groundcrew stop the ac from flying
A: Yes, they raise a 707B and state that the aircraft has a fuel leak and this needs to be rectified before flying, additionally, because of a what they found above, they can say we have found a source of ignition in a wiring harness and it will be fixed before we can safely sign the aircraft off, it would take a brave man as an engineering officer to say sign the card up and authorise the aircraft to go flying against the experience and advice from the groundcrew and results from the Immediate actions taken post the crash of XV230.
Again don't stop asking questions, but as has been said before there is a lot of Nimrod experienced aircrew/groundcrew, and ex of the same, who also want to help you with a resolution, but are trying to stop you going of in the wrong direction.