Anybody remember the MP Michael Mates? Many, many moons ago I listened to him being interviewed on the radio during a long, boring road trip. He had been on a defence committee and he explained that whenever he asked a question the MOD did not want to answer, they simply claimed the information was "classified" and prejuducial to national security. Could have been about the cost of NAAFI biscuits...made no odds.
Given that context, yer mans answer is as unwaveringly a "standard response" as all the others over the past few decades. Roughly translated it means "too difficult, go away".