Why did Kakashi...

[Saikyokami]

She wouldn't let him do **** with her.

 

[Kharon Of The Leaf]

I thought Kishi hinted towards Rin being a Rain-nin or spy. I thought that could be the only reason that the rain shinobi that where there when it happened didnt want her body returned to the leaf. Remember that the bodies of shinobi hold village secrets, such as the body Jiraiya gave the leaf from Pien of the Rain.

 

[Zatack]

I thought Kishi hinted towards Rin being a Rain-nin or spy. I thought that could be the only reason that the rain shinobi that where there when it happened didnt want her body returned to the leaf. Remember that the bodies of shinobi hold village secrets, such as the body Jiraiya gave the leaf from Pien of the Rain.

If this is the case then i'm fine with it, but its usually always more than that in this series.

 

[Narutoga]

We dont really know why kakashi killed rin, manga has not said it yet

 

[namikaze12]

No one knows but a lot has come to the conclusion that she was a spy

 

[MWQ]

I think it happened by accident.The hidden mist have been known to cast a mist which limits one's movement and possobly blinds them.In the confusion rin probably got killed.

 

[KyuubiHatake]

I wanna know to

 

[Nous]

Only Kishimoto knows

 

[The Madara Uchiha]

I thought it mentioned her being in enemy hands so Kakashi killed her to protect the leaf.
It was something along the lines of he HAD to.