Incredibly, no one from any Nazi security service was ever punished for this colossal failure. Not even Christian Weber (the de-facto Nazi mayor of Munich) who was officially in charge of security arrangements for Nazi functions in the city (including the Bürgerbräukeller event).
This leniency (and the VIP-treatment of the bomber in KL) predictably gave rise to a conspiracy theory. According to this theory, Elser had been a secret member of the SS and the whole assassination attempt had been staged by the Nazis to portray Hitler as being protected by Providence.
This theory made little sense to anyone familiar with the realities of the Third Reich and was finally debunked (and thus put to rest) in 1969. Careful analysis of all relevant documents performed by a German historian Anton Hoch proved beyond the reasonable doubt that Elser, indeed, had acted alone and that there was no evidence of the involvement of the SS or any outside group in the assassination attempt.
However, this verdict means that there has to be another explanation for such forgiveness on the part of Adolf Hitler (the trait he had definitely not been known for). In other words, why on Earth did he not order officers responsible for his security at Bürgerbräukeller demoted, transferred to the front, imprisoned, sent to KL or shot (Stalin would have undoubtedly done the latter to everyone responsible for this colossal security failure)?
The only reasonable explanation that comes to mind is that Hitler simply did not care. All he cared about was the proof of his Divine protection by the Almighty Providence that this failed attempt made beyond the reasonable doubt.
And Himmler and Heydrich had no desire to launch the official investigation because it very well could have led straight to them (because of the omnipresent Führerprinzip). Hence they (like their boss) simply let this matter slide.
The same year, another individual (by the name of Erich Kordt) planned the assassination of Adolf Hitler. His reason was simple – he was a diehard Anglophile and simply could not stand Great Britain suffering from the war with Germany.
He was a professional diplomat with extensive experience dealing with the British (not surprising given the fact that his English was better than his German) so he knew for a fact that as long as Adolf Hitler is in power, the United Kingdom will not make peace with Germany.
So he decided to kill Der Führer after the Oster conspiracy did not result in the assassination of Hitler (the latter was saved by Britain and France signing the infamous Munich agreement).
He hatched an assassination plot (in partnership with another diplomat – Hasso von Etzdorf). Their idea was not exactly original – they wanted to plant a bomb… somewhere and detonate it when Adolf Hitler shows up.
However, Nazi security services apparently learned their lesson from the Bürgerbräukeller disaster and (finally) made acquisition, transportation and concealment all but impossible. So the conspirators had to abandon their plan.
In April 1941, Kordt was posted to Tokyo as German embassy First Secretary and later to Nanking as German Consul, where he (surprise, surprise) worked as an agent for the Soviet spy Richard Sorge until 1944.
He narrowly avoided being killed by a Japanese hitman when Japanese Intelligence discovered his espionage activities (as a diplomat, he had immunity and thus was off limits for Japanese police). Von Etzdorf resigned after the French campaign and did not play an active role (either pro- or anti-Nazi) in politics.
Unbelievably, Nazi security services learned only one lesson from the Elser debacle. Hitler’s personal security was still lax (to put it mildly), so the Providence had to interfere again and again to save him from being assassinated by the Resistance killers.
In 1943, General der Gebirgstruppe (mountain troops) Hubert Lanz – himself a war criminal – developed a plan together with Generals Hans Speidel (a Mussolini-style fascists who abhorred racial theories of the Nazis), Hyacinth Graf Strachwitz (recipient of the Knight’s Cross of the Iron Cross with Oak Leaves, Swords and Diamonds for bravery and superb leadership) and Paul Loehning to assassinate Hitler during his visit to the Army Detachment Kempf in Ukraine.
According to the plan, Generalleutnant Hyacinth Graf Strachwitz was to surround Hitler and his escorts with his tanks (he was in command of the Panzerregiment “Großdeutschland”).
Lanz stated that he would have then arrested Hitler, and in the event of resistance, Strachwitz’s tanks would have shot and killed the entire delegation (that was brutally creative). However, the Providence evidently had other plans for Adolf Hitler, so he abruptly canceled the visit and the plan had to be dropped.