Game freezes in Combat Start if I switch to Cautious just before a battle

I actually reported this with the demo, as it occurred with the very first small spider attack in the demo.

Twice now in the Bone Castle I have hit cautious mode when I see enemies approaching. Then I pause and set an attack (ranged) to surprise the foes. So far so good. However the game says Combat Starts but then just freezes. Requires a reload from last save to fix (and then go into cautious mode earlier)