I imagine that what seems a high level to an ordinary person is far less high for a person who has a very high tolerance to drugs.
In his book Matt spoke openly about acquiring drugs illicitly through doctor contacts. I can see him quite easily acquiring additional ketamine to supplement the therapy.
This is a man who battled demons each and every day. I can only imagine what a lonely struggle life is for an addict. It was a miracle he was still alive given the toll his decades long addiction had taken on his body and mind.
People are quick to judge drug addiction and are unable to imagine themselves in that position. It's so important to remember this is a mental illness we're talking about.
Sadly, Matt is a very good example of how you can have fame, charisma, millions in the bank and still be unhappy. This was a troubled lonely man and I really hope that the autopsy doesn't change his legacy.
I can unfortunately see naive people saying 'but he lied about being clean, he was on drugs'. It's not that black and white. He deserves to be remembered for the important work he did to help those with addiction.
Rest in peace, Matt.