I agree with your sentiment CB, and I understand how you feel.
Thing is, been riding the wheel of life for quite a while now and have some personal experience with betrayal of trust.
That and I'm much meaner about these things.

Consider.

There can not have been more than a few people that knew of the grow.
It was in a secured area with limited access.
No attempt at a red herring, (Little cat fur, some rat shit, broken window pane, jimmy marks, etc.)
So, this guy's elevator does not go all the way to the top floor, yah?

My best instinct is to try to help him with his need for ethics, but.
In my experience, that kind of stupid, goes to the bone.
You can't fix that!

But there's also no need to compromise your own self-esteem.
Karma may be slower, but it's thorough and imaginative.
When ya do shitty things you lose respect for yourself!
And "No matter where you go, there you are!"

My advice is to maintain enough connection for a front row seat to this train-wreck of a person.
Unrecognized guilt is insidious, and will seek punishment, he will set himself up for a fall, over and over.
Without dirtying your hands with this prick, you will have your revenge many times over just watching him screw himself up.

If you live long enough and pay attention, I'm betting you will come to the same understanding.
Why wait?

Aloha,
Weeze