Seems like this would be very condusive to the dramatic style of FATE gameplay, especially if the person has to get into the gritty details of exactly how they make the damage worse. Heck, you could even use something like that to your advantage.
"rather than dodging, I jump straight into the knife, wedging it between my ribs, and grab hold of the guy's arm." Now you've got a higher damage tier involved, AND at the DM's discretion the enemy might take a penaty to dodging whatever you do next, or be unable to move away.