I’ve never had that happen, ever. How traumatizing for you and him too. Maybe when you have had time to grieve you can get a chuckle out of it. You said it-he went out like he lived. Difficult to the end-on his terms.
Did you really expect anything else?
I’m smiling as I write this, horrifying for sure, but from what you have described, it doesn’t surprise me. He had to throw that one last fit. It could have been the pain and fear he was already suffering and for that, you can smile with love in your heart because he is no longer suffering.
Go outside, put your hands on your head. Pull those last moments, that last bad memory, out of your thoughts. Cup your hands, and bury them under a rock. Sounds silly, but it’s a good mind trick. Decide to remember them no more and only remember the love you shared and love all his quirky ways.