I understand that 'I don't recall' is the safest legal answer to difficult questions, as it's not a categoric yes or no, but I'm not sure it's the wisest look for the PM (if indeed he gives a fuck).
This was the most significant peacetime crisis this country has faced and one of the key political leaders through all of it is repeatedly suggesting he can't remember the most basic detail about its defining moments. Mind you, playing dumb is perhaps the least-worst card in his pack.