That was anime. Anime bullshitted and changed shit. They didn't want to fucking insult religious people in anime.
1. Ryuk, notebook, light gets it.
2. Kills L.
3. Mikimi ends up seeing him as not a god.
4. He gets shot up.
5. Begs mikimi for help, he says "YOU'RE NOT GOD"
6. He begs misa, whos not there, then begs ryuk. Ryuk then says "alright i'll write down names".
7. Turns book around, lights name on it.
8. Explains about he would write down name at end of lifespan.
9. Says "remember, people who use the death note neither go to heaven or hell" then laughs.
10. Flashback to light, who the first time ryuk said it light said "thats because there is no heaven or hell right?"
11. Ryuk says "blah blah thought all humans believed, thats right, all death is equal, human shinigami, etc all go to nothingness".