Ok i have not heard anything about this before but when you hit someone with a knife will they be knocked down like when you normally bash?
Thanks and discuss the possibility!

Nope, but knife deals more damage than a normal bash

http://brinkvault.com/2011/04/get-smart-video-series/

Have a look there Explains the whole process and pros/cons. I think it's the third vid.

They specifically say that knives DON'T knock down, but do extra damage to compensate.

I think your're getting the slide knock down mixed up with the knifing.