Dan W.: the "Gestapo conspiracy" hypothesis had been popular in the last months prior to the full-blown French campaign. It went more or less like this: the Reich government needed a
casus belli to justify an assault on France and Britain and to gain sympathy for the Führer from the general population. Therefore they planted a bomb carefully timed to avoid death or injury for any senior National Socialist and blamed it on the British undercover agents.
The theory got disproved over time by Elser's own testimonies and survivor accounts, but the Gleiwitz Incident was still fresh in the people's memory (contemporary newspaper and survivor diary accounts from around the Gleiwitz Incident show most people in Europe and the USA disbelieved the version of the Polish assault, even as no proof was going to be uncovered prior to Naujocks' trial 6 years later).
Sample of press reaction:
The Spectator, 24 November 1939, Page 2:
The Munich Bomb Story
No one is surprised that Herr Himmler, Chief of the German Police, has succeeded in finding a scapegoat for the bomb explosion in the Munich Beer Cellar on November 8th, or that the investigations have been so manipulated as to attribute the blame to the British Secret Service. The only surprise is that Mr. Churchill is not personally implicated. The German official statement gives a detailed account of the laborious devices by which Georg Elser contrived to commit a crime declared to have been organised by Otto Strasser, and instigated and financed by the British Intelligence Service. Elser was arrested, it is stated, on the night of the crime. The full incriminating evidence is alleged to have been collected by the Police Special Com- mission before November i4th, when Georg Elser, under what pressure of Third Degree examination we are not told, made full " confession " about his own crime and his accomplices. It is strange that the police, when they already had such abundant proof of the author of the outrage and knowledge of all that happened, should continue to offer rewards to anyone who could give information and issue a description of the wanted man. The whole story is a con- coction according to recipe. It is too clumsy to deceive any but the most credulous of Germans. No one outside Germany will give a moment's credence to the invention that the British Secret Service or its agents had anything to do with the crime. This country, no doubt, like every belligerent country, is alert in the search for military news, but its record is a guarantee that assassination is not among its weapons.
A Romanian senior journalist sympathetic to Socialism and Communism wrote in his diary entry for 24 November 1939:
"to make it credible, they should have sacrificed a few of their own. Why shouldn't loose, and such loss would be no big deal indeed, say, Goebbels, his dog-like jaw?..."
PS A forum poster once asked: if Elser was so sure he left behind no clue to point towards him, why did he attempt to cross the Swiss border having plenty of incriminating objects upon him: sketches, a fuse ...
Communist Party membership card? Simply keeping silence and a low profile in the poorer neighborhoods of Munich would hide him like a needle hides in a haystack.