Correcting silicon between plasterboard
The problem, although difficult, can be solved. If the silicone has squeezed out from the drywall joint it needs to be cut. With a utility knife slice away all dried silicone that is above the surface of the drywall. The lower the better. Don't be overly concerned about damaging the drywall panels; don't butcher them, but don't preform surgery either. After the silicone is removed spackle and tape as usual. BTW I see screw heads in the photo, I'm guessing he used them until the silicone dried? FYI: it is not uncommon to use an adhesive to mechanically secure gypsum panels in place, but to be sure I've never come across silicone as the adhesive! Question: Is the contractor refusing to tape and spackle his drywall installation?