Technique to kill your rival

[TheGZA]

i heard if you choke someone long enough they die

I think that's just a rumor.

 

[Xuh]

 

[Vile]

I heard that getting kneereaped can kill you

 

[dudeguyman]

I am just wondering that, if there are techniques to break most of your rival bones, at least without good defence, how is it that is there no technique that just kill your rival if he is taken by surprise?
In striking, attacks to the throat are not allowed because they are too dangerous. But what about grappling?

Go learn at class.