They knew Hitler was losing it long before, but at that point they were literally fearful Hitler was going to have them all shot.
In December 1941 Fritz Todt, Hitler's Armaments Minister, compared American and German production of steel, aluminum, coal and crude oil.
He came to a simple conclusion.
"The war can no longer be won militarily
Two months later Fritz Todt died in a plane crash.
Coincidence?