You don't want to understand, no?

What is the D supposed to do when he investigates a G and you say he can't show himself? The Gs know that he found a G and the Cs are out in the blue knowing nothing. Big advantage to the Gs.
If the D finds a G he better shows himself and helps the Cs, the Gs know what's going anyway and with the information of who got investigated it makes it easier to guess who the d is for them.
And I'm not even voting you.