7.0 AQ Spoiler.The Rule of death

What if Dottore died because he was nearing the end of his research on the elixir of immortality and the rule of death worked? If this is the case, then we need to understand that he was not reborn because he was old and weak, and his soul was somehow divided into segments and was not well anchored to his body. Or did he just not have time to be reborn because the segments simply opened him up and let his body go for research?