I was listening to 𝔉𝔩𝔬𝔬𝔡 today and he was going over Himmler. He reviewed this David Irving oration. This is the first time I've ever heard the narrative of how Himmler committed suicide.
It doesn't make any damn sense.

So the scenario that is envisioned must be that Himmler ditched the casing and had the ampule in his mouth (presumably for many hours) and bit it when the doctor tried to look in his mouth.“I think the reason it’s become such a popular pop culture trope is because there have been a number of people who have hidden cyanide capsules in their mouths, and certainly they use their teeth to use it,” says Vince Houghton, curator at the International Spy Museum in Washington, D.C. “Himmler’s a good example of this. Actually there are a lot of Nazis that chose that way out.”
While the guy is talking, intelligibly, with an entire fucking cigar butt in his mouth basically...There, he was stripped and given a blanket to wear because he would not put on a British uniform before being medically examined by a British doctor. Once more the medic was looking for SS cough drops. Again, the British doctor found no sign of the so-called lethal pill. While Murphy listened, Himmler ranted how he was too important to deal with “underlings.” He wanted to talk to General Dwight D. Eisenhower, supreme commander of Allied forces in Europe. From that, he went on to the need for the Western Allies and the defeated Germans to band together to fight against the Soviet Union before it was too late.
Watching all this, the British doctor started to have second thoughts. Himmler was too confident, too smug. It was as if he still had some last ace up his sleeve. He stopped the interrogation and asked Himmler to come over to the window where there was more light. He wanted to look into the German’s mouth. It was then that Himmler must have realized the game was up.
As the medical officer put his finger into Himmler’s mouth and spotted the cyanide capsule, Himmler bit down hard. The doctor yelled and pulled out his bitten finger in the same instant that Himmler swallowed the contents of the hidden capsule.