At this juncture, I want us to look at the potential risk by which this my friend has come to expose himself.
Or is there a smart move of him you can commend of him on that?
I can't speak for your friend and how he trusted his crypto-related activities to him, but it looks like your friend and his buddy has known each other for a long period of time so there is really a valid reason why he trusted his friend that much, let alone telling us that the friend has been with hin in the ups and downs of his life.
There is indeed a risk involved but with the risk he has established evidence and witness that he acquired his cryptocurrency in a non-illegal way. I know you are concerned about that friend but it was his choice of action and all you can do is pray and hope that the one your friend trusted won't betray him.
It is ok to be vigilant but it should be in the right place. Whether the guy's friend will betray him is for us to see, but hopefully, that guy can really be trusted.