If the basis for suing Glock is that the the officer's pistol did not come equipped with a grip safety, well, it's pretty clear to me that Glock never offered or implied that it sells such a thing. There is no fault on the part of the manufacturer; the suit does not appear to be claiming that the pistol was defective, rather merely that it lacked a certain feature that the company never claimed was there in the first place.
At best I could see the guy being allowed to bring suit against his department for procuring an insufficiently idiot-proof service weapon. But unless he is claiming a manufacturing defect, then Glock is clearly not part of this story. They never claimed to offer external safeties; they did not force the department to buy that model; they did not provide the weapons training to the officer; they did not put the pistol in reach of the child.
So, yeah, I think the judge who allowed this go through is prize moron who would appear to have no problem reinstating a frivolous lawsuit against an innocent company, and my inner cynic tells me the judge probably thinks it's okay to punish an 'evil' gun company. A pox on him.