Well what I'm saying is that even if you can't prove a specific corpse's identity you can prove a corpse with that identity exists, which is different. If you prove someone is dead without a corpse a corpse is guaranteed you just have to find it.
Anyway What I'm also saying is that since Kinzo is dead at the start of all games anyway (whether it's dead dead or personality dead) it could just be a coincidence that the gold seems to apply to all games. Because in this particular case it already did apply to all games previously. So there is nothing saying the gold can't apply to only one game.