I think your concern that the assailant will/can turn the weapon against you is oversimplified. Here's why:
1) Who's to say that the assailant won't be "WTF! this bitch has a gun!" and be equally stunned
2) Disarming an armed person isn't exactly "easy" when all you have to do is take 1 step back (a natural reaction anyone would have to someone lunging at them) to avoid most scenarios, at least initially. Allowing you to overcome analysis paralysis, if any.
3) Upon seeing an armed person, a criminal, especially if they are out "gunned" hehe, may just decide to GTFO.
Assuming a fight over a weapon occurs and you lose your weapon
3) Does it matter if they brought a knife to a house invasion, only to find a armed person, who is then disarmed and they then use that weapon to complete the crime? In the end it's still an armed house invasion.
4) Unless you have a particular phobia does it matter whether you are then stabbed (you didn't have a gun) or shot (because you were disarmed), but survive?
5) If you die in the process, it's all kinda moot whether it was by knife or gun.