Earlier quoted context omitted.
And then he killed himself to set off moronic conspiracy theories as a final FU to the USA.
Which is more believable, that he was murdered, or that he killed himself to troll people?
He killed himself to damage the reputation of the US government.
He couldn't escape from imprisonment, and he couldn't do much to harm the government. But he could do this.
It was the most he could do, so (I think) it's what he did.