Now this is something that I want to see and learn. CANNOT be harmed? There is a 0% possibility of uke being harmed, no matter how dumb and self destructive they are? wow! I can't make a cup of coffee with that kind of guarantee, let alone do a definite shihonage.
Okay, I know I am being pedantic and picking on what was most likely a slip of the tongue (or fingers). Did you mean "there is a very small likelihood of uke being harmed"?
As I said, harmless techniques. If you understand the principles involved then the word cannot fits. Otherwise I should use the words 'should not'