Mouse knife was pretty cool, but the more I think about it the worse it seems. Only one cutting edge, not much mass but decent speed, poorly designed for thrusting. I think mouse knife is a weapon that looks scarier than it is. It's good at distracting someone but not at putting them down. Best scenario is it gives them a few cuts, puts them off balance, then you move in close and strangle them with the cord.
This being a MacGyver situation I'll give it an "B+." Actual MacGyver would have collapsed the entire building with an I.E.D.