Sorry to hear of your loss, particularly when you were trying to help this guy must make it so much worse. I hope that his inability to act in a human fashion does not continue to taint your attitude towards other people who may be in a time of need.

I hope that at some stage this guy is able to appreciate the consequences of his inability to resist temptation. Obviously the opportunity you unwittingly presented was too much for him to resist.

Perhaps some of it may be returned in time? Good luck.