Mueller helped cover up 9/11, the Anthrax attacks and helped orchestrate the WMD lies that led to invading Iraq. I'd say that's a pretty strong betrayal in the countries time of need.
There's nothing to debunk. Mueller was director of the FBI for a decade, during which time he helped cover up 9/11 and lied the US into the disasterous war in Iraq. This is his resume.
If you're trying to argue that Mueller has repented his former Deep State ways and is now working for Q and the White Hats, well that's a different argument. But don't obfuscate Mueller's known shady past.