Tex. Civ. Prac. & Rem. Code § 151.011

The special judge's verdict must comply with the requirements for a verdict by the referring court, including any applicable requirements for the issuance of a written opinion. The verdict stands as a verdict of the referring judge's court. Unless otherwise specified in an order of referral, the special judge shall submit the verdict not later than the 60th day after the day the trial adjourns.