I can't.
I agree he is angry but the best he can do is send stern memos. He can't be everywhere at once.
Another time they planned to close McClellan AFB, CA, and someone from a closed door only meeting leaked it to then Governor Reagan who promptly went after the Commander. The Commander put out a memo and said it may take awhile but he would track that person down and fire them on the spot. They tracked the person and he was gone! AFLC Council Members were tight lipped after that!
Would imagine there are some aides tracking down who was at the meeting and who could possibly be the leaker. If you have information that came out and put it against just who was in the meeting you should be able to narrow it down. Sometime down the road that person or persons will wish they never compromised our military.
Oh, there are ways to find leakers. It just depends on two things: do you have the time and initiative to set the canary traps, and do you have the will to act on the results?