Ouchy! Did he recover OK?
I've considered stunned but I wonder about the value. One thing that I've heard alot about in other places is that F/T has a much lower parasite risk. If its not a true live feed then I know of no advantage to not going F/T - except that its a pain.
A number of people have said that the risk with stunning is that the rodent might wake up early and be really P.O.'d.
The other option I've considered is "de-arming" of the prey item. Of course, a little claw clipping is no big deal but when it comes to the teeth I can't think of anything that isn't too cruel or too risky.