At a slow (eg walking) speed, can uke escape from your shihonage by changing the speed?
Let's take this to an extreme: I will try to do shihonage so that I'm barely even moving and uke gets to move at whatever speed he or she wants. In fact, let's say I'm not moving at all. Clearly, uke will have no difficulty contorting their body, releasing the pressure on their arm and punching my lights out.
Their are many interesting things to learn when going slowly. One of them is to become sensitive to the subtle shifts and changes in uke's movement and make subtle adjustments to keep the technique 'working.' Clearly, I have to be allowed to adjust at the same rate as uke in order for this to make any sense.
Of course, it could be a very interesting exercise to let uke shift speeds at will and, as nage, try to feel and match those speed shifts. That's a different issue, though.