In Closs v. Goose Creek Consol. Indep. Sch. Dist., 874 S.W.2d 859 (Tex. App. -- Texarkana 1994, no writ), the Court found the error harmless where the trial court did not state the particulars of good cause.
In that case, the Court stated that " the trial court, by failing to specify the particulars of the good cause supporting its order striking the affidavit, has not so obscured its reasoning as to prevent Closs from being able to present this issue on appeal." Id. at 880.