davoravo

To reiterate Justin and Peter

If you train in such a way that any technique is permissible to Uke's attack then Uke is never wrong.

However, the vast majority of us train kata style with a fixed response to a fixed attack. If Uke delivers the wrong attack then that leaves Nage in a difficult position of either changing the technique or failing the technique.

I mean changing technique completely rather than adjusting the technique as usually Uke is doing something strange like pulling down so all the directions of force are wrong.

So I vote Uke can be wrong