My condolences Steve, this is just my opion so take it for what its worth...
My wife is/was a hospice nurse for years and has told me stories of things she encountered that can only be described as not of this earth but more spiritual than anything. Patients that had been unresponsive to any stimuli, organs shuting down, O2 sats in the low 80s, BPs so low she thought they were passing right then, just a shell, would sit up, eyes clear, words were spoken with such clarity and wisdom, often speaking to others that had passed many years prior....so I truly believe that there are things communicated to us and through us that we really have no comprehension of. This might have been one of those moments.
Let stuff go, if you hang on to that kind of anger it will just fester inside. Don't waste your time on it, life is too short to hang on to things that cause nothing but regret and hate and gives less room to appreciate the small things.
Take that energy spent dweling on what he did and celebrate the positives in life, family, friends & mopars! Like one of the other members said here a while back, " you're letting them have you rent free" .. or something really close to that.
Peace!