Just agreeing with others: the injured feather preceded the feather removal. Chronic feather plucking is quite different and begins with your grey plucking healthy down, semiplume and contour feathers (on it's chest) -- generally not important feathers like wing feathers.
Any time my grey gets an injured wing feather, I always just hope he will just remove it himself. The exception is a split/broken blood feather, spurting blood -- in which case I support the wing and pull the feather's base out completely with a pliers (pulling in the direction the feather is growing). Because such a broken blood feather can act as an open catheter causing major blood loss, it's urgent the entire feather base is pulled so coagulation can occur. Again, we're talking only about blood feathers, not mature feathers. Hope you never have this happen).
My grey is smart, and if he can repair the damage himself (with feather removal), I just leave it alone for him to handle it. Sometimes they can't fix the problem, and then it's my responsibility to pull a damaged feather myself if I see it poses a risk to him. Usually it's just a twisted feather (no bleeding) and my guy knows to remove it.