As far as I can remember there is a ground launch override switch like in the A-10C, I just can't remember where it is off the top of my head.
edit: I'm an idiot. The switch I'm thinking of isn't implemented in the cockpit, and I'm not sure it even does what I was think it does.
However I did try to launch RB-75T's while sitting on the parking ramp and they do work. So I'd agree that something is wrong with that.