This is most likely not a typo. Sometimes "accidents" happen and you accidentally do something you didn't intend to.
This is similar to the Stress Crit table. There are sections where the stress is good for you i.e.: beneficial stress - the mom able to lift the car off of her child pinned under the car, the firefighter able to endure the heat to toxic environment to rescue 5 people, then collapses outside. Not all stress is bad.
In the case of the subduing crit, one could argue you nailed the exact, pin-point, spot to render the foe unconscious... however, you didn't hit it with enough force, or you slipped and it was too much force, or the foe has a medical condition
and the foe went unconscious. Whatever hypothetical you want to argue, the precision was there, the execution was poor.