Threshold between natural causes and non-natural, for the dragon ball revival/resurrection wishes?

[Warmmedown]

Goku's heart virus was natural (you've gotta read virus the Japanese way)
Earthlings indirectly blown up on Earth was unnatural
Vegeta's suicide was unnatural

What about if Goku hadn't managed to use Freeza's spaceship and died on Namek?
What about if you ran from Imperfect Cell and fell from high up?
What if your vision went blurry from a lack of glucose and you fell out of a window?
What if you went on hunger strike to protest the lack of water in Nam's village and died?
What if you're killed by a robot like Android 19 or the pirate robot?

 

[Dagon]

People eaten by animals: It's the circle of life.

 

[SSJ2]

What about if you ran from Imperfect Cell and fell from high up?

Imperfect Cell is a natty.

 

[Yoshi]

What about if Goku hadn't managed to use Freeza's spaceship and died on Namek?

I imagine it would be the same situation as Krillin’s death on Namek.