I once had a situation, not exactly the OP's premise but close:
I was out of work (first time in 13 years). At the time I had a wife and 2 small children at home. We were hurting financially. My cousin, let's call him Roger for the sake of privacy, came by one night asking to borrow some money. I flat out told him I couldn't do it. My situation was bleak, getting an IT job at the time was very difficult and my wife's job barely kept us afloat. I explained all of that to him but he kept pressing and promising that he'd pay me in a week, it was an emergency, that he understood my situation and wouldn't let me down... blah blah blah...
I caved, gave him a small loan after making sure he understood that he had to keep his word. To make a long story short, didn't see Roger's face again for 6 months. In the interim I'd found a job and was back on my feet. One day I'm in the market getting checked out and here comes Roger... "hey cuz! what's up?" he says.. the look i gave him would have meant something to most folks but Roger apparently wasn't phased in the least. I asked him to wait in the parking lot, we had some business, he said fine. I go to the lot like 2 minutes later, the guy is gone...
I'm livid. I finally catch up to Roger and give him the business (verbally) and he practically shrugs it off "sorry, my bad" he said... I was spent, that was it. If he caught on fire I wouldn't piss on him to put him out. I was done with him. After that I'd see him around from time to time and he'd greet me like nothing happened, I'd barely nod but that didn't stop him. I cut him a break because he was family (the worse kind sometimes) and his mother (my aunt) was chronically ill and didn't need to deal with him and I going at it.
Roger lived with his mother on the same street I did, so i'd see him around from time to time. One day I'm leaving the house going to work and there's cops and police tape down the street. I go down to see what's the ruckus and there, lying on the ground in a pool of coagulated blood, is Roger... shot dead sometime overnight. His body was covered but I knew it was him. Another neighbor who knew we were cousins walked up to me and hugged me, said how sorry she was and what not but I felt absolutely nothing... I wasn't angry, bitter, happy or sad. it was like looking at roadkill.
No one in the crowd was surprised really. It was almost expected. Apparently I wasn't the only person he stole from (if you can call what he did stealing, I do) Roger finally conned the wrong person. He paid his due.
Then a funny thing happened, I started to feel guilty about my lack of emotion. Was I being petty? A man, a relative, just lost his life and I, for all intents and purposes, didn't really care. It wasn't life changing money I lost in comparison to the value of the man's life. I tried to put it in perspective, tried to tell myself I was being petty but I have yet to feel an ounce of emotion about it. I was pissed at first. I told him my situation and he screwed me without a second thought.
Yes, it was ultimately my fault for giving him the cash but we were blood, that was supposed to mean something to him. So i'm i'm not angry but I don't think I care enough to forgive (if that makes any sense)....