For what its worth Chiba Sensei doing tsuri otoshi, kiri otoshi against someone with no tsuba is not a good idea for the recipient of Chiba Senseis waza. Even with a tsuba one can easily get hit on the hand.
Of course you have to be able to respond to the attack and not rely on a tsuba. Learning to absorb the force applied by tori with ones total body is the trick.One needs to relax and try to neutralise the power of the strike.Even with a padded shinai one can still receive a stout whack on the knuckles if you are not careful.Motto-do not get hit!! Cheers, Joe.
This kind of supports what Graham is saying though. Nobody would get hit in the hands particularly hard if you trained at a speed and intensity level you could handle. People get hurt when they get sloppy, and that should tell you to slow down and work on precision.