You refer to approaching that person "in the next life" with anger as if that's somehow relevant. It isn't.
My ex-wife cheated on me and left me for another guy over 20 years ago. When it happened, I was sad. I was also a little angry with both of them for creating such a difficult situation for me and my sons. I had to get beyond that and I eventually did. My feelings were selfish. I had 2 sons to take care of. Being sad and moping didn't help them.
If someone had told me the day after I heard about her sexual escapades that my sadness/anger was selfish, I doubt it would have been helpful. I do know what was helpful, however, and that was time and giving myself an opportunity to heal. I did that.
We don't know when Joysey will die. Maybe he died in the last few minutes and carried his fresh emotion with him. My guess, however, is that he's not dead and won't be dead for a while. He'll have time to cope and heal. Maybe you're telling him that his feelings that sprung from something that happened only hours ago are inappropriate is what helps him heal most, but I'd guess not.
Instead, it sounds like an insensitive move on your part.