Although Churchill's name is not mentioned, the allusions to the highest possible authority being a "cigar-smoking" "elderly gentleman" are clear enough. The meeting came about when Hutton had to justify having Red Cross parcels in his office. In his book he insists that he was only investigating their contents, not thinking of incorporating his escape tools into them. Including military supplies in Red Cross packages would have contravened the Geneva Conventions, and would also have risked having those parcels and others withheld from the POWs. He eventually used other channels to sneak in his inventions, such as "donations" to POW camps of unused books - which happened to have maps and currency hidden in their covers.
Upon hearing Hutton's confirmation that his work had been legitimate, Churchill goes on to give a description of the planning for the war:
Always remember that at the end of this war we want to be in a position to say that we fought and won it fairly. I think you’re trying to go much too quickly. Reconcile yourself to the fact that it takes us four years to attain victory. In the first year we have to sell the war to the public; in the second we are busy jiggering and tooling for the latest weapons; in the third supplies come pouring in; and in the fourth we press buttons everywhere and the enemy has a most unpleasant time. So cultivate patience and - keep your hands clean.
Which is quite good advice in general, and particularly here as we approach the peak of this Crisis.