
On Stanley Baldwin, as cited in Churchill by Himself (2008), Ed. Langworth, PublicAffairs, p. 322 ISBN 1586486381
Also quoted by Kay Halle in Irrepressible Churchill: A Treasury of Winston Churchill's Wit http://books.google.com/books?id=b0MTAQAAIAAJ&q=%22Occasionally+he+stumbled+over+the+truth+but+hastily+picked+himself+up+and+hurried+on+as+if+nothing+had+happened%22&pg=PA133#v=onepage (1966).
The 1930s
Variant: Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing ever happened.