I think, totally unsupported by any evidence, that this guy used it to show the Germans where the weak points on the Halifax were and what technological advantages we had they didn’t know about.
Nothin’ like automatically assuming the absolute worst about someone you don’t even know.
Your comment reminds me of the “Hogan's Heroes” episode where Hogan offers to tell Klink all about the “Norton” for a trade of some sort. Klink thinks it is for the Norton Bomb Site, and Hogan draws a sketch of the Norton Vacuum Cleaner. "And the accuracy is great because of this extra long handle and the curve on the grip...."