I'm so sorry this happened to you. But it wasn't your fault and it sounds like the owner was way over the line, grief or not. I'm glad you didn't give him money or your information. The dog shouldn't have been running loose. I would have a very difficult time coping with this (it's one of my greatest fears) so I can only send you empathy but please don't blame yourself. Have you talked to a therapist about this? That would be my first action just to help get the awful memories out of my head.