Friends and family investors who put cash into the Well can’t really be fired either, even if they are contributing other things as long as their primary role is investment. They would keep their slices with the multipliers, no matter what happens. You could offer to buy them out with the 4x multiplier (which would be a nice return), but they shouldn’t be forced to sell.
If an investor wants her money back they can ask for it which is the same thing as quitting. In these cases you would have to pay them back without the multiplier if you can afford it.